MEDICAL 


Medical  Library  Exchange 


University  of  Oregon 
Medical  School  Library 


LABORATORY    DIRECTIONS 


GENERAL  BIOLOGY 


BY 

HARRIET    RANDOLPH,     PH.D 

Demonstrator  in  Biology  and 
Reader  in  Botany,  Bryn  Mawr  College 


"Willst  Du  in's  Unendliche  schreiten, 
Geh1  erst  im  Endlichen  nach  alien  Seiten." 

— GOETHE, 


NEW  YORK 

HENRY   HOLT  AND   COMPANY 
1898 


• 


1 


Copyright,  1897, 

BY 

HENRY    HOLT    &    CO. 


ROBERT  DRUMMOND,    ELECTROTYPER   AND   PRINTER,    NEW   YORK. 


PREFACE. 

THE  following  laboratory-directions  have  been  pre- 
pared for  a  course  in  General  Biology  that  extends 
throughout  the  collegiate  year,  and  includes  work  in  the 
laboratory  for  about  six  hours  each  week. 

Experience  has  shown  that  there  are  certain  practical 
advantages  in  beginning  with  the  fern  and  the  earth- 
worm, and  that  the  results  are  not  at  all  inferior  to 
those  that  follow  from,  the  more  logical  method  of 
beginning  with  the  simplest  organisms. 

The  plan  of  this  course  is  similar  to  that  suggested  by 
the  ' '  General  Biology  "  of  Sedgwick  and  Wilson ;  and 
as  the  directions  have  been  used  with  large  classes  for 
several  years,  it  is  believed  that  they  are  entirely  practi- 
cable. 

In  determining  the  amount  of  work  to  be  done  upon 
each  form,  an  endeavor  has  been  made  to  include  the 
most  important  points  and  at  the  same  time  to.  keep 
each  in  its  proper  relation  to  the  other  parts  of  the 
course  as  a  whole.  But  any  suggestion  of  improvements 
that  may  occur  to  any  one  using  the  directions  would  be 
gladly  received  by  the  author. 

The  following  list  of  hours  has"  been  found  by  experi- 
ence to  represent  approximately  the  time  needed  for  the 
different  subjects : 

iii 


297* 


IV 


PREFACE. 


Hours. 
Preliminary    practice    with 

microscope 3 

Fern 10 

Earthworm 10 

Amoeba 2 

White  blood-corpuscles 1 

Hsematococcus 4 

Paramoecium 2 

Vorticella 2 

Yeast 5 

Peuicillium  \ 

Lichen          C 4 

Mushroom    ) 

Bacteria 2 

Spirogyra 2 

Hydra 4 

Mussel...  .  5 


Hours. 

Lobster 4 

Moss « 5 

Stern,  bud,  leaf 4 

Flower 4 

Seeds 2$ 

Seedlings 4 

Seed-contents „.  4 

Circulation,  etc.,  of  proto- 
plasm  „ 2 

Karyokinesis 2 

Frog 12£ 

Fish 2 

Pigeon  6i 

Rabbit 10i 

Embryology: 

Frog 6* 

Chick..  ..16 


At  the  present  time  laboratory-directions  in  a  course 
in  General  Biology  necessarily  presuppose  the  use  of 
subjects  and  to  some  extent  of  methods  employed  by 
previous  writers.  For  the  mode  of  presentation  of  cer- 
tain topics  my  acknowledgments  are  due  especially  to 
Prof.  E.  A.  Andrews  and  to  Prof.  V.  M.  Spalding. 

To  Prof.  T.  H.  Morgan,  who  has  been  so  good  as  to 
read  and  criticise  the  directions  for  Invertebrates,  Plants, 
and  Embryology,  and  to  Prof.  J.  W.  Warren,  who  has 
kindly  advised  me  in  regard  to  the  Vertebrate  work,  it 
gives  me  great  pleasure  to  acknowledge  my  indebtedness. 

H.  R. 

BKYN  MAWB  COLLEGE,  June  1897. 


TABLE  OF  CONTENTS. 


PAGE 

INTRODUCTION 1 

PRELIMINARY  PRACTICE  WITH  THE  MICROSCOPE 5 

FERN 7 

EARTHWORM 13 

AMCEBA 24 

WHITE  BLOOD-CORPUSCLES 26 

H^EMATOCOCCUS 27 

PARAMCECIUM 30 

VORTICELLA ,  33 

YEAST 36 

PENICILLIUM 39 

LICHEN 41 

MUSHROOM , 43 

BACTERIA 45 

SPIROGYRA 48 

HYDRA 52 

FRESH-WATER  MUSSEL 58 

LOBSTER 66 

Moss. 75 

SPERMAPHYTES .  79 

Stem 79 

Root 82 

Bud 82 

Leaf 83 

Flower 84 

Seeds 87 

Seed-contents 90 

Seedlings 91 

V 


vi  TABLE  OF  CONTENTS, 

PAGE 

ROTATION  AND  CIRCULATION  OF  PROTOPLASM  . , 93 

KARYOKINESIS . .     94 

FROG 95 

FISH 113 

PIGEON 116 

RABBIT 128 

EMBRYOLOGY 143 

Frog  .' 142 

Chick..  146 


GENERAL  INTRODUCTION. 

I.  THE  MICROSCOPE  AND  ITS  USE. 

The  microscope  *  consists  of  a  stand,  a  tube,  and 
lenses.  Attached  to  the  column  of  the  stand  is  a 
horizontal  plate,  the  stage,  which  holds  the  object 
to  be  examined. 

In  the  middle  of  the  stage  is  a  round  hole 
through  which  light  can  be  directed  upward  by  a 
mirror  which  is  attached  to  the  stand  below  the 
stage.  The  amount  of  light  can  be  regulated  by 
diaphragms. 

The  stand  gives  support  above  the  stage  to  a 
vertical  cylinder  in  which  the  tube  slides  up  and 
down. 

The  combination  of  lenses  to  be  inserted  into 
the  upper  end  of  the  tube  is  the  eyepiece  (or  ocu- 
lar) ;  that  at  the  lower  end  the  objective. 

The  objective  AA  is  a  low  power,  D  is  a  high 
power. 

Objective  AA,  eyepiece  2  magnifies  about  50 
diameters. 

Objective  AA,  eyepiece  4  magnifies  about  90 
diameters. 

*  The  description  applies  to  the  Zeiss  microscope,  Stativ  VII, 
with  oculars  2  and  4,  objectives  AA  and  D. 


2  GENERAL  BIOLOGY. 

"-/ 

Objective  D,  eyepiece  2  magnifies  about  240 
diameters. 

Objective  D,  eyepiece  4  magnifies  about  420 
diameters. 

To  be  seen  clearly  an  object  must  be  at  a  definite 
distance  from  the  objective.  Moving  the  lenses  to 
the  proper  place  is  called  focussing. 

For  finding  the  focus  there  are  two  adjustments. 
The  coarse  adjustment  is  used  especially  with  the 
low  power ;  it  may  be  used  also  with  the  high 
power  for  finding  the  approximate  focus ;  it  con- 
sists in  sliding  the  tube  up  or  down  with  the 
fingers.  This  should  always  be  done  with  a  slight 
twisting  movement.  The  fine  adjustment  is  effected 
by  means  of  a  screw  with  a  milled  head  behind  the 
tube.  It  is  used  to  focus  the  lens  exactly  after  the 
object  has  been  brought  into  view  with  the  coarse 
adjustment. 

The  following  rules  should  be  carefully  ob- 
served : 

1.  Always  examine  an  object  first  with  the  low 

power  (AA). 

2.  Never  use  the  high  power  (D)  unless   the 

object  is  covered  with  a  cover-glass,  Be 
very  careful  never  to  let  the  objective 
touch  the  cover-glass. 

3.  Remember    that    objects    can    be    brought 

clearly  into  view  only  by  the  hand,  not 
by  the  eye.  If  the  object  is  not  dis- 


GENERAL  INTRODUCTION.  3 

tinctly  visible  do  not  strain  the  eye  to  see 
.  it,  but  by  means  of  the  line  adjustment 
alter  the  focus  of  the  microscope.  In 
order  to  bring  different  parts  of  an  object 
into  view  the  focus  must  be  continually 
changed,  and  for  this  reason  the  hand 
should  always  be  kept  on  the  fine-adjust- 
ment screw.  If  this  rule  be  observed 
there  is  little  danger  of  injuring  the  eyes. 
If  the  object  cannot  be  brought  clearly 
into  view  by  focussing,  see  whether  the 
mirror  reflects  as  much  light  as  possible, 
that  the  objective  is  not  wet,  and  that  the 
cover-glass  is  clean. 

4.  The  lenses  must  be  perfectly  clean.     Dust 

on  the  lens  obscures  the  image,  and  may 
strain  the  eye.  To  clean  a  lens,  breathe 
upon  the  glass  in  order  to  dampen  it,  and 
then  wipe  it  with  a  soft,  fine  cloth  kept 
for  this  purpose  alone.  A  lens  should 
never  be  touched  with  the  fingers,  as 
these  often  leave  ineffaceable  marks. 

5.  Look  through    the    microscope    sometimes 

with  one  eye  and  sometimes  with  the 
other,  and  keep  both  eyes  open ;  the 
strain  upon  the  eyes  is  by  this  means 
much  lessened. 

6.  Lenses,  when  not  in  actual  use,  should  be 

protected  from  dust  and  injury. 


4  GENERAL  BIOLOGY.  . 

7.  The  tube  of  the  microscope  should  always 

slide  smoothly.  If  it  does  not,  take  it 
out,  wipe  it  clean,  and  apply  a  little  vase- 
line. 

8.  When  lifting   the   microscope,  do  not  take 

hold  of  the  column  above  the  stage,  as 
this  is  apt  to  disarrange  the  fine  adjust- 
ment. 

9.  When  not  in  use,  the  microscope  should  Tse 

put  into  its  box  (observe  paragraph  8). 
Each  objective  should  be  put  into  its  own 
brass  box  with  the  lid  that  corresponds 
(otherwise  the  thread  of  the  screw  may 
be  injured,  and  the  boxes  cannot  be 
tightly  closed,  to  keep  out  moisture,  etc.). 

II.  ON  DRAWING. 

Everything  of  importance  should  be  recorded  by 
sketches  or  diagrams  and  by  notes.  Try  to  show 
in  the  sketches  as  clearly  and  accurately  as  possible 
the  essential  features  of  what  has  been  seen,  and 
add  concise  explanations.  In  order  to  show  the 
natural  relations  of  the  parts  it  may  be  necessary 
to  combine  several  views  of  the  object. 

Draw  on  a  large  scale ;  the  sketches  cannot  be 
too  large. 

It  is  best  to  draw  to  scale,  i.e.,  either  the  exact 
size  or  half  or  double,  etc.,  the  size  of  the  object. 

Name  the  parts  represented  in  the  drawing,  and 


GENERAL  INTRODUCTION.  5 

mark  the  scale  adopted,  as,  e.g.,  X  2  when  the  draw- 
ing represents  the  object  twice  its  size. 

The  outlines  should  first  be  traced  very  lightly 
with  a  soft  pencil,  so  that  they  may  be  readily 
altered.  When  the  sketch  is  complete  the  outlines 
may  be  gone  over  with  a  harder  pencil  or  with  ink, 
and  the  different  parts  may  be  made  more  distinct 
by  slightly  shading  them  with  colored  crayons. 

Outlines  should  not  be  sketched  in  color.  Certain 
colors  should  be  used  for  special  organs  or  tissues. 

PRELIMINARY  PRACTICE  WITH  THE  MICROSCOPE. 

I.  Scales  from  the  wing  of  a  butterfly. 

Take  with  a  scalpel  some  of  the  colored  parti- 
cles from  the  wing,  place  them  upon  a  slide 
and  examine  with  AA  2,  Compare  the  ob- 
ject as  it  appears  when  illuminated  by  the 
the  mirror  ("  transmitted  light"),  and  when 
the  light  from  below  is  cut  off  ("reflected 
light").  Examine  successively  with  AA  4, 
D  2,  D  4,  and  make  a  series  of  outline 
sketches  of  a  few  of  the  scales  to  show  the 
difference  in  magnifying  power. 
II.  Put  a  few  fibres  of  wool  into  a  drop  of  water 
upon  a  slide.  Put  on  a  cover-glass  and 
examine  first  with  a  low  and  then  with  a  high 
power.  Note  the  form  of  the  fibre  by  care- 
fully focussing  at  different  levels.  Sketch 
CD  2). 


6  GENERAL  BIOLOGY. 

III.  Examine  bubbles  of  air  in  water.  To  obtain 
these,  support  a  cover-glass  by  a  thick  piece 
of  filter-paper  under  one  edge,  run  a  drop 
of  water  under  the  cover  glass,  and  then  tap 
the  glass. 

The  cover-glass  must  be  supported  so  that 
the  bubbles  may  be  spherical.  Sketch 
(AA  2).  (Keep  for  comparison  with  IV.) 

IY.  Examine  a  small  drop  of  oil  suspended  in  water 
with  the  cover-glass  supported.  Compare 
the  air  and  the  oil,  and  note  the  differences 
in  the  appearance  of  each  upon  focussing  up 
and  down.  Sketch. 

V.  To  make  a  scale.  Find  on  a  stage  micrometer,* 
with  the  low  power,  the  lines  ruled  one 
millimetre  and  one  tenth  of  a  millimetre 
apart.  Draw  some  of  these  as  they  appear 
projected  upon  paper  at  the  base  of  the 
stand.  While  doing  this  keep  both  eyes 
open  and  the  head  motionless.  Draw  sev- 
eral sets  of  lines,  and  then  transfer  the  most 
accurate  set  to  a  piece  of  cardboard. 

Make  a  scale  for  the  combinations  AA  2, 
D  2,  and  D  4 ;  label  each  with  the  names  of 
lenses  used,  and  the  actual  size  of  the  mi- 
crometer spaces. 

*Zeiss's  Object-micrometer,  No.  26,  b. 


FERN. 

PTERIS  AQU1L1NA. 

A.  ASEXUAL  GENERATION. 

I.  External  characters. 

1.  Rhizome — the  brown,  underground  stem  with  a 

ridge  on  each  side. 

2.  Roots  ;  springing  from  the  rhizome. 

3.  The  leaves  or  fronds:  arising  from  the  rhizome 

at  intervals  along  the  lateral  ridges. 

(a)  The  subdivision  of  the  frond :   the  leaf- 

stalk or  stipe,  and  the  leaf  proper  or 
lamina.  The  lamina  is  subdivided  like 
a  feather  (pinnately)  into  pinnae;  each 
pinna  is  pinnately  subdivided  into 
pinnulae,  the  pinnulse  in  some  cases  into 
lobes,  and  these  into  lobules. 

(b)  The  sorus:  a  band  of  sporangia  under  the 

edge  of  some  of  the  pinnules. 

(c)  The  mdusium ;  the  membrane  covering  the 

sorus. 

4.  The  nodes  and  internodes  of  the  rhizome. 

5.  The  growing  point  at  the  end  of  the  rhizome. 
/Sketch,  slioioing  these  parts. 

II.  The  rhizome. 

1.  Cut  one  end  smooth  with  a  razor  and  sketch  the 

cut  surface  as  seen  with  the  naked  eye. 
(a)  The  outer  brownish  layer  :  epidermis  and 
subepidermis   (sclerotic  parenchyma);  the 

7 


8  GENERAL  BIOLOGY. 

subepidermis    thinner    at    the    lateral 
ridges. 

(b)  The    light-colored    ground- substance    or 

fundamental  parenchyma,  forming  most  of 
the  stem. 

(c)  The  dark  interrupted  ring  of  sclerenchyma 

(sclerotic  prosenchyma). 

(d)  Small  patches  of   sclerenchyma    outside 

the  main  ring. 

(e)  Yellowish     tissue     (fibrovascular    bundles) 

lying   ID  side    and   outside    the   ring  of 
sclerenchyma. 

2.  Cut  a  small  piece  of  rhizome  in  a  longitudinal 

vertical  plane. 
Find  on  the  cut  surface  (a),  (6),  (c),  (d),  (e\  in 

II.  1. 
Sketch. 

3.  Cut  a  thin  transverse  section  of  rhizome,  mount 

in  water,  and  examine  with  the  low  power. 
Find  the  different  kinds  of  tissues,  as  in  II.  1, 

(a),  (6),  (c),  (d),  (e). 

Make  a  diagram  to  show  the  outlines  of  the  different 
regions. 

4.  Treat  the  section  with  iodine  and   observe   the 

result.  To  treat  with  iodine  put  a  drop  or  two 
of  iodine  on  the  slide  close  to  the  cover-glass, 
and  on  the  opposite  side  of  the  cover-glass  draw 
away  the  water  from  under  the  cover-glass  ivith 
a  small  piece  of  filter-paper. 


FERN.  9 

5.  Examine  a  prepared  stained  transverse  sec- 
tion of  rhizome.  Study  with  the  high 
power. 

(a)  Find  again  the  tissues  in  II.  1,  (a),  (6),  (c), 
"(a)"  The  epidermis:  a  single  layer  of  cells 

with  very  thick  walls ;  the  subepi- 
dermis  (sclerotic  parenchyma) :  with 
thick-walled  cells. 

"  (&)"  The  fundamental  parenchyma :  large 
thin-walled  cells  with  protoplasm, 
nucleus,  and  starch-grains. 

"  (c)"  Sclerotic   prosenchyma :   smaller  cells 

with  thick  walls. 
Sketch  a  few  cells  of  each  kind. 

(b)  In  the  fibrovascular  bundle  note  : 

1.  On   the    outside    a    single   layer   of 

flattened  cells  with  brownish  walls 
and  apparently  empty  (bundle- 
sheath). 

2.  Within  the  bundle-sheath  a  layer  of 

parenchymatous  cells  containing 
starch  (phloem-sheath). 

3.  Within    the    phloem-sheath    is    the 

phloem,  consisting  of : 

(a)  Small  cells  with  thick  walls  (bast- 

fibres). 

(b)  A  single  row  of  large  thin- walled 

cells  (sieve-tubes  or  bast- vessels). 

(c)  Small  thin-walled  cells  lying  be- 


10  GENERAL  BIOLOGY. 

tween  (a)  and  (5),  and  contain- 
ing starcli  (phloem-parenchyma). 
4.  Within  the   phloem  is  the  xylem  or 
wood.     !N-  te  : 

(a)  Large  eir    tj  vessels  with   thick 

walls  (tracheids). 

(b)  Small  vessels  (tracheae). 

(c)  Small  parenc          '-cells   contain- 

ing  starch,  i     spaces  between 
the  angles  of  vessels  (wood-pa- 
renchyma). 
Sketch  the  outline   of  a  fibrovas<.  "       bundle  and 

some  cells  of  each  kind  in  their  relation  to  one 

another. 

6.  In  a  prepared  longitudinal  sec.     ••  find  the 

kinds  of  cells  just  seen  in  tra  sec- 

tion. 
Sketch. 

7.  Crush  a  piece  of  rhizome  that  has  been  v>>  >cerated, 

and  ivith  the  high  power  find  the  var-      ^  kinds 
of  cells  now  more  or  less  isolated.     xS/w.  'eft. 
III.  The' Leaf. 

1.  Strip  off  a  piece  of  the  epidermis  from  th    1wver 
side  of  the  leaf,  mount  in  water,  and  no. 

(a)  The    ordinary  epidermis-cells  with  \v 

outlines. 

(b)  The     guard-cells,    two    surrounding    each 

stoma. 
Sketch  accurately  (much  enlarged)  two  guard-cells, 


FERN.  1 1 

a  few  of  the  ordinary  epidermis-cells  sur- 
rounding. 
2.  In  a  prepared  vertical  section  of  a  leaf  note  : 

(a)  The  epidermis-cells  of  upper  and  lower 

surface.  Look  for  stomata  and  guard- 
cells. 

(b)  Mesophyll-oells  containing  much   chloro- 

phyll. These  cells  are  arranged  near 
the  upper  surface  of  the  leaf  in  com- 
pact layers,  but  near  the  lower  surface 
they  are  irregularly  placed,  with  air- 
spaces between  them. 

(c)  Transverse    or   oblique    sections   of    the 

fibrovascular  bundles. 
Sketch  a  part  shoiving  (a)  and  (b). 
IV.  Asexual  Reproductive  Organs. 

1.  Examine  a  part  of  the  sorus  with  a  low  power 

without  a  cover-glass. 

It  is  composed  of  a  number  of  oval 
bodies  :  the  sporangia,  covered  by  the  in- 
dusium.  Sketch. 

2.  Remove  some  of  the  sporangia,  mount  in  water \ 

examine  ivith  high  poiver,  and  sketch.    Note  : 

(a)  Form  :  biconvex  bodies,  borne   on  short 

stalks. 

(b)  Structure :  flat  cells,  with  one  row  thick- 

ened to  form  a  prominent  ring  (annulus) 
around  part  of  the  capsule. 


12  GENERAL  BIOLOGY. 

m 

(c)  Mode  of  debiscence  (look  for  one  that  has 

opened). 
3.  Spores.     Examine  with  high  power.     Note  : 

(a)  Size.     (Measure.) 

(b)  Form. 

B.  SEXUAL  GENERATION.     Prothallium. 
I.  Examine  a  prothallium  with  the  naked  eye  or  a 
hand-lens,  then  mount  in  water,  and  examine 
with  the  lowest  power. 
Sketch.      Turn  it  over  and  sketch  again. 
II.   Reproductive  organs. 

1.  Examine  the  lower  surface  of  the  prothallium 
with  the  high  power.     Note  : 

(a)  Archegonium :    a    chimney-like   structure, 

brownish  in  late  stages.  In  the  cavity 
at  the  bottom  lies  the  oosphere.  /Sketch. 

(b)  Antheridium :    a  rounded  projection  with 

an  outer  layer  of  cells  containing  a  few 
chlorophyll-grains.  In  different  stages 
of  development  there  can  be  seen  in 
the  centre  either  a  single  cell  or  a  num- 
ber of  smaller  cells  (mother-cells  of 
spermatozoids)  produced  by  the  divi- 
sion of  the  central  cell.  The  mother- 
cells  in  ripe  antheridia  contain  spirally 
coiled  bodies  (spermatozoids).  /Sketch. 


EARTHWORM. 

LUMBRICUS     TERRESTRIS. 

A.  OBSEEVATIONS  ON  THE  LIVING  WORM. 

I.  Put  a  living  worm  upon  a  sheet  of  paper  on  the 
laboratory  table  and  observe  its  shape  and 
its  movements.  (Be  careful  not  to  let  the  worm 
become  dry.) 

1.  Note  tlie  changes  of  form  of  the  anterior  and 

posterior  parts  of  the  body  as  the  worm 
moves  over  the  paper.  In  what  way  is 
this  change  of  shape  brought  about? 

2.  With  a  blunt  instrument  touch  one  end  and 

then  the  other  end  of  the  worm.  Which 
end  is  more  sensitive  ? 

3.  Note    the    pulsations    in    the   dorsal   blood- 

vessel (visible  through  the  skin  along  the 
median  dorsal  line).  What  is  the  direc- 
tion of  the  wave  of  contraction  ? 

B.  EXTERNAL  CHARACTERS  OF  THE  PRESERVED  SPECI- 

MEN.* 

I.    With  the  worm   extended  in  a  dissecting -pan  and 

covered  with  water  or  with  iveak  alcohol,  observe : 

1.  The   division  of   the   body   by   constrictions 

into  a  number  of  segments  or  somites  (me- 

*  For  method  of  preservation,  etc.,  see  ' '  General  Biology,"  Sedg- 
wick  and  Wilson,  second  edition,  1895,  pp.  210-213. 

13 


14  GENERAL  BIOLOGY. 

tamerism  or  serial  symmetry).  Count  the 
number  of  somites. 

2.  Modifications  of  the  somites : 

(a)  At  the  extreme  anterior  end  a  smoothly- 
rounded  knob,  the  prostomium. 

(6)  Swellings  on  the  ventral  side  of  some  of 
the  somites  between  the  7th  and  the 
19th,  the  capsulogenous  glands. 

(c)  Between  the  28th  and  the  87th  somites 
a  swollen  region,  the  clitellum. 

3.  The   anterior    and    posterior    ends   are   not 

alike  (antero-posterior  differ entiation). 

4.  The  dorsal    and    ventral    sides    are    unlike 

(dorso-ventral  differentiation). 

5.  When  the  worm  is  placed  with  the   ventral 

side  down  a  longitudinal  vertical  plane 
will  divide  it  into  similar  right  and  left 
halves  (bilateral  symmetry). 

6.  The    stiff  bristle-like   setae:   felt  by  drawing 

the  worm  gently  through  the  fingers. 
With  the  naked  eye  or  a  hand-lens  note  the 
arrangement  of  the  setse. 

7.  The  openings  to  the  outside  : 

(a)  The  mouth:  close  to  the  anterior  end  on 

the  ventral  side  below  the  prostomium. 

(b)  The  openings  of  the  seminal  receptacles: 

on  each  side  between  the  9th  and  10th 
and  the  10th  and  llth  somites  (four 
openings;  difficult  to  make  out). 


EARTHWORM.  15 

(c)  The    openings   of    the   oviducts :    one   on 

each  side  on  the  ventral  aspect  of  the 
14th  somite. 

(d)  The   openings   of   the   vasa  deferentia :    a 

conspicuous  slit  surrounded  by  swollen 
lips,  on  each  side  on  the  ventral  aspect 
of  the  15th  somite. 

(e)  Dorsal  pores :  one  in  each  somite  after  the 

first  two  or  three,  in  the  median  dorsal 
line. 

(/)  Nephridial   openings :    one    pair   in   each 
somite.    (These  cannot  be  seen  with  the 
naked  eye.) 
(g)  The  anus :  a  vertical  slit  in  the  posterior 

(the  anal)  somite. 

Make  two  enlarged  drawings  (X  3  or  X  4)  of 
the  anterior  end,  a  dorsal  and  a  ventral 
view,  showing  the  first  forty  somites ;  and  a 
sketch  of  the  posterior  end,  dorsal  aspect, 
showing  the  last  ten  somites. 

C.  ANATOMY. 

I.  Extend  a  freslily  killed  worm  dorsal  side  upper- 
most in  a  dissect  ing -pan  and  fasten  it  to  the  wax 
by  a  pin  at  each  end  (the  anterior  pin  through 
the  prostomium  only).  Cover  the  worm  with 
50  per  cent,  alcohol.  With  fine  scissors  cut  care- 
fully through  the  dorsal  body-ivall  a  little  to  one 
side  of  the  median  line.  Note : 


16  GENERAL  BIOLOGY. 

1.  The  body-wall  consisting  of  three  layers  : 

(a)  The  cuticle. 

(b)  The  hypodermis. 

(c)  The  muscular  layer. 

2.  The    space  between  the  body-wall  and   the 

alimentary  canal,  the  body-cavity  or  ccelom. 

3.  The    thin   muscular   partitions   (dissepiments) 

which    divide   the  ccelom  into  a  series  of 

compartments. 

II.  Cut  through  the  dissepiments  on  the  left  side  close 
to  the  body-ivall ;  spread  out  the  body -wall  and  pin 
it  to  the  wax  (putting  the  pins  in  obliquely).  Sim- 
ilarly for  the  right  side.  Note : 

1.  The  alimentary  canal :  a  straight  tube  extend- 

ing throughout  the  whole  length  of  the 
body. 

2.  The   nephridia :    delicate,  whitish    bodies    at- 

tached by  one  end  to  the  posterior  side  of 
a  dissepiment,  and  by  the  other  end  to  the 
ventral  body- wall ;  one  on  each  side  of  the 
alimentary  canal  in  each  somite. 

3.  The    seminal  vesicles :    three   pairs    of   white 

bodies  lying  partly  at  the  sides  of  the 
alimentary  canal  and  partly  above  it,  be- 
tween the  9th  and  the  12th  somites. 

4.  The    dorsal    blood-vessel :    a   long    tube    lying 

upon   the    dorsal   side  of   the  alimentary 
canal.     It  gives  off : 
(a)  The    aortic    arches:    five   pairs    of    large 


EARTHWORM.  IT 

contractile  vessels  that  pass  down 
around  the  digestive  tract  in  somites 
7  to  11. 

(b)  Smaller   circular   vessels :    some   passing 
into  the  walls  of  the  intestine,  others 
along  the  dissepiments  into  the  body- 
wall. 
5.  The  parts  of  the  alimentary  canal : 

(a)  The  buccal  pouch  :    an   eversible  sac   into 

which  the  mouth-opening  leads.  (It 
lies  in  somites  1  and  2,  and  should  not 
be  dissected  out  until  after  the  nervous 
s}-stem  has  been  studied.  See  C.  II. 

7,  (/)-) 

(b)  The  pharynx  :   an  elongated  thick-walled 

pouch  extending  from  the  2d  to  the  7th 
somite.  Numerous  small  muscles  con- 
nect it  to  the  body-wall. 

(c)  The  oesophagus :  a  thin-walled  tube  much 

smaller  in  diameter  than  the  pharynx, 
extending  from  the  6th  to  the  15th 
somite.  (More  distinctly  seen  when 
being  taken  out ;  C.  II.  6.) 

(d)  The  crop :  a  thin-walled  dilatation  of  the 

alimentary  canal  at  about  the  16th 
somite. 

(e)  The  gizzard :  a  thick-walled  muscular  sac 

at  about  the  17th  somite. 
(/)  The  stomach-intestine :  a  thin-walled  tube 


18  GENERAL  BIOLOGY. 

extending  from  the  gizzard  to  the  anus. 
It  is  expanded  into  lateral  pouches  or 
diverticula  in  each  somite. 
(g)  The  chloragogue  cells :  the  yellowish-brown 
pigmented  layer  covering  the  outside 
of  the  stomach-intestine. 

Make  a  diagrammatic  sketch  (X  4)  of  the  parts 
included  under  C.  II.  1  to  5  (g). 
(h)  Open  the  crop,  the  gizzard,  and  the  stomach- 

intestine  by  a  lateral  cut. 

Examine  the  character  of  the  wall  of  each, 
and  note  in  the  stomach-intestine  the  thick 
longitudinal  ridge,  the  typhlosole,  which 
projects  into  the  intestinal  cavity  from  its 
dorsal  side. 
Make  a  diagram  of  the  stomach-intestine  as  it  would 

appear  in  transverse  section. 
6.  The  reproductive  organs. 

[To  see  the  reproductive  organs,  cut  until  fine  scis- 
sors through  the  alimentary  canal  close  behind 
the  gizzard,  and  holding  the  cut  end  of  the 
gizzard  with  fine  forceps,  raise  it  carefully  and 
cut  through  the  attachment  of  the  dissepiments 
(disturbing  them  as  little  as  possible);  cut  the 
alimentary  canal  across  behind  the  6th  somite 
and  remove  the  entire  oesophagus.] 
In  taking  out  the  oesophagus  look  in  the  llth 
and  12th  somites  for  three  pairs  of  calcifer- 


EARTHWORM.  19 

ous  glands:  small  pouches  attached  to  the 
sides  of  the  oesophagus. 
Observe : 

(a)  The  seminal  vesicles  :  three  pairs  of  rela- 

tively large,  opaque  white  bodies  lying 
at  the  sides  of  the  oesophagus.  In  the 
mature  worm  the  posterior  pair  grow 
together,  forming  a  posterior  median 
vesicle  lying  ventral  to  the  alimentary 
canal  in  the  llth  somite  ;  and  the  two 
anterior  pairs  in  a  similar  way  form 
one  anterior  median  vesicle  in  the  10th 
somite.  Cut  off  the  tip  of  one  of  the 
vesicles,  mount  in  water  on  a  slide,  and 
examine  with  the  high  power.  Look 
for  different  stages  in  the  development 
of  the  spermatozoa.  (Cf.  "  General 
Biology,"  Sedgwick  and  Wilson,  second 
edition,  p.  77.) 

(b)  The   funnels  ("ciliated  rosettes")   of  the 

vasa  deferentia  (seen  in  the  mature 
worm  by  carefully  opening  the  median 
seminal  vesicles) :  two  pairs  of  rosette- 
like  bodies  with  opaque  white  borders 
in  the  10th  and  llth  somites. 

(c)  The  vasa  deferentia:  four  fine  ducts  run- 

ning posteriorly  from  the  four  funnels. 
The  two  of  the  same  side  unite  in  the 
12th  somite  to  form  a  single  duct  on 


20  GENERAL  BIOLOGY. 

each  side,  which  runs  back  and  opens 
to  the  outside  in  the  15th  somite. 

(d)  The   testes  :    four    small,    opaque    white 

bodies  with,  finger-like  lobes,  attached 
one  on  each  side  of  the  median  line  to 
the  posterior  side  of  the  dissepiments 
9-10  and  10-11.  In  the  mature  speci- 
men they  are  enclosed  by  the  median 
seminal  vesicles. 

(e)  The  seminal  receptacles :  two  pairs  of  white, 

rounded  sacs  in  the  9th  and  10th 
somites.  Their  short  ducts  open  to 
the  outside  in  the  constrictions  be- 
tween the  9th  and  10th  and  the  10th 
and  11  th  somites,  respectively. 

(/*)  The  ovaries:  two  pear-shaped  bodies  at- 
tached to  the  anterior  wall  of  the  13th 
somite,  one  on  each  side  of  the  median 
line. 

(g)  The  oviducts:  two  short,  funnel-shaped 
tubes  passing  through  the  dissepiment 
between  the  13th  and  14th  somites,  one 
on  each  side  of  the  median  line.  They 
appear  often  as  thickenings  of  the  dis- 
sepiment. 
Make  an  enlarged  diagram  of  the  reproductive 

organs. 
7.  The  nervous  system. 

Central  nervous  system.     Observe: 


-EARTHWORM.  21 

(a)  On  the  dorsal  side  of  the  pharynx  in  the 
2d  or  3d  somite  a  pair  of  pyriform 
white  bodies  united  in  the  median  line  : 
the  cerebral  ganglia. 

(b)  From  each  lobe  a  nerve-cord,  the  circum- 

cesophageal  commissure,  passes  down  at 
the  side  of  the  pharynx,  in  the  con- 
striction between  the  bnccal  sac  and 
the  pharynx,  to  the  suboasophageal  gan- 
glion (first  ventral  ganglion)  on  the  lower 
side. 

(c)  From  the  suboesophageal  ganglion  a  long 

double  ventral  nerve-cord  passes  poste- 
riorly in  the  mid  ventral  line. 
Peripheral  Nervous  System. 

(d)  Two  large  nerves  which  run    anteriorly 

from  the  cerebral  ganglia. 

(e)  A  nerve   from  each   half  of   the   circum- 

03sophageal  commissure  near  the  union 
of  the  two  halves  on  the  ventral  side. 
(/)  Typically  three  pairs  of  nerves  in  each 
somite  :  two  pairs  arising  from  the  gan- 
glion and  one  pair  (septal  nerves)  from 
the  cord  immediately  behind  the  dis- 
sepiment. 
Make   a   diagram  (X  6)  of  the   nervous   system. 

(At  this  point  the  buccal  sac,  C.  II.  5.  (a),  may 

be  looked  for.) 


22  GENERAL  BIOLOGY. 

8.  The  cuticle. 

With  forceps  strip  off  under  water  the  cuticle  from 
the  lateral  and  ventral  aspects.  Mount  it  in 
ivater  on  a  slide,  and  examine  first  ivith  a  low 
and  then  ivith  a  high  power. 

With  the  low  power  observe  : 

(a)  The  tubular  processes  of  the  cuticle  torn 

from  the  setae-sacs. 
With  the  high  power  observe  : 

(b)  The  thin  transparent  membrane  not  com- 

posed of  cells.  It  is  traversed  by  deli- 
cate lines  and  perforated  by  minute 
pores. 

9.  Before    leaving   the   anatomy   of   the    earth- 

worm see  a  demonstration  of  a  nephridium 
from  a  recently  chloroformed  worm. 
10.  Make  a  drawing  ( X  5)  of  an  egg-capsule. 

D.  MICROSCOPIC  STRUCTURE  OR  HISTOLOGY. 
I.  Prepared  transverse  section. 

For  detailed  directions  see  "General  Bi- 
ology," Sedgwick  and  Wilson,  second  edition, 
1895,  pages  91  to  95  inclusive. 
Make  a  diagram  shotving  in  outline  the  different 

regions  of  the  section. 
Sketch  accurately,  much  enlarged,  a  portion  of  the 

section  a  few  cells  in  ividth. 

Make  an  accurate  sketch  of  the  cross-section  of  the 
ventral  nerve-cord. 


EARTHWOEM.  23 

II.  Prepared  longitudinal  sections  to  show  the  re- 
lations of  cerebral  ganglia,  alimentary  canal, 
circumoesophageal  commissure,  and  ventral 
nerve-cord. 

1.  Section  through  the  median  region  (cerebral 

ganglia,    alimentary  canal,    ventral   nerve- 
cord). 

2.  Section   at   one   side   of   the   middle   region 

(circumoesophageal  commissure). 
Diagrams  in  outline  ! 


AMCEBA. 

Mount  some  of  the  water  or  sediment  containing 
amoebae  under  a  large  cover-glass.  /Search  for 
them  with  the  low  poiver,  and  when  found  study 
tvith  the  high  poiver.  Observe  : 

I.  General  Characters. 

1.  Form :  in  the  motile  state  characterized 
by  irregularity  and  continual  change  ; 
rounded  processes  (pseudopodia)  formed  by 
the  protrusion  and  the  retraction  of  the 
protoplasm. 

II.  Structure. 

1.  An  outer  transparent  layer :  the  ectoplasm. 

2.  An  inner  more  granular  layer  :  the  entoplasm. 

3.  A  spherical  or  disk-shaped  body  in  the  ento- 

plasm :  the  nucleus. 

4.  A  spherical  space  filled  with  fluid,  disappear- 

ing and  reappearing  at  intervals ;  the 
contractile  vacuole,  often  situated  in  the 
hinder  part  of  the  body.  If  the  pulsations 
can  be  readily  observed,  describe  them. 

5.  Water-vacuoles   (not  always  present) :  in  the 

entoplasm. 

6.  Food    masses   in   food-vacuoles  in   the    ento- 

plasm. 
Sketch  an  amoeba  ( X  8  or  X  10). 


AM(EBA.  25 

III.  Movements.     Observe: 

1.  The  mode  of  formation  of  a  pseudopodium. 

2.  The  process  of  locomotion. 

3.  If   possible,  the    taking   in  of   food  and  the 

passing  out  of  waste  matter. 
Make  a  series  of  outline  sketches  at  regular  intervals 
to  show  the  changes  of  form. 

4.  The   effect   of   higher   temperatures   on   the 

movements  of  an  amoeba.     (Heat  gradually 
on  a  warm  stage*     Record  the  result.) 

IV.  [Reproduction. 

If    an  amoeba  be  found  dividing  by  fission,  ob- 
serve and  sketch  it. 
Y.  Chemical  and  Mechanical  Tests. 

1.  Treat  with  magenta   or  iodine.     Record  the 

result. 

2.  Crush  a  stained  specimen.  Describe  the  result. 

*  A  simple  warm  stage  may  be  made  of  sheet  copper  the  width 
of  a  glass  slide  and  several  times  its  length,  with  a  hole  pierced 
an  inch  and  a  half  from  one  end  to  correspond  to  the  aperture  of 
the  diaphragm.  To  use  the  stage,  place  it  on  the  stand  of  the  mi- 
croscope and  fasten  the  slide  down  upon  it  with  the  microscope- 
clips.  To  heat  the  copper,  place  a  lighted  alcohol-lamp  under  the 
free  end.  A  simple  method  of  determining  when  the  temperature 
of  the  slide  has  reached  approximately  38  degrees  is  to  place  upon 
it  a  small  fragment  of  paraffine  that  has  been  mixed  with  suffi- 
cient benzole  to  reduce  its  melting-point  to  the  desired  degree. 


WHITE  BLOOD-CORPUSCLES. 

A.  Mount  under  a  cover -glass  supported  by  a  piece  of 

hair  or  a  bristle  a  drop  of  blood  obtained  by  prick- 
ing the  finger  near  the  root  of  the  nail  with  a  fine 
needle.  Surround  the  margin  of  the  cover-glass 
with  vaseline.  Make  the  preparation  as  quickly 
as  possible  in  order  that  it  may  not  dry. 
Disregard  the  colored  corpuscles  and  look  for  the 
less  frequent  white  ones.  Observe : 

I.  General  Characters. 

1.  Form :    irregularly   rounded ;    changes  occur 
as  in  amoeba,  but  more  slowly. 

II.  Structure. 

1.  Granular  protoplasm. 

2.  Nucleus  (rarely  visible  in  the  fresh  state). 
Sketch. 

III.  Movements. 

Place  the  preparation  on  a  loarm  stage  and  heat 
gradually  to  38  degrees  C.  Record  the  result. 

B.  Mount  in  the  same  way  corpuscles  of  the  codomic 

fluid  of  the  earthworm.  This  may  be  obtained 
by  exposing  the  worm  for  a  moment  to  the 
vapor  of  chloroform,  when  the  fluid  will  exude 
through  the  dorsal  pores  j  touch  a  cover-glass  to 
the  fluid  and  instantly  mount. 

Note  the  shape,  and  changes  of  form  that  may 
occur. 

Sketch, 


H/EMATOCOCCUS. 

A.  KESTING  STAGE.* 

Mount  on  a  slide  some  sediment  containing  hcema- 
tococcus  that  has  been  soaked  for  a  feiv  hours 
in  water.  Cover  and  examine  with  a  low  power. 
Find : 

I.  External  Characters. 

1.  Red  or  green  spherical  cells. 
With  a  high  power  observe : 

2.  Size.     (Measure.) 

3.  Form. 

4.  Color  :  red,  green,  or  in  some  cells  both  red 

and  green. 

II.  Structure. 

1.  Colorless  cell-wall. 

2.  Cell-contents:    more   or   less  granular;   con- 

sisting of  protoplasm,  a  centrally  situated 
nucleus  and  superficial  chromatophores  in 
which  the  coloring  matter  is  deposited. 
(The  outlines  of  the  chromatophores  are 
difficult  to  distinguish  in  the  living  state. 
The  nucleus  is  more  easily  seen  in  the 

*  Haematococcus  can  sometimes-  be  found  in  old  marble  urns. 
When  once  obtained  the  same  supply  will  last  for  a  number  of 
years.  It  should  be  wet  each  year  with  spring-water,  and  is  be- 
lieved to  flourish  better  if  a  little  powdered  marble  is  added. 

27 


28  GENERAL  BIOLOGY. 

smaller,    green   form,    Pleurococcus.      See 
below.) 
Sketch  (X  6). 

3.  Look  for  cells  whose  contents  are  undergoing 

endogenous  division.     Sketch. 

4.  Treat  with    iodine.     What    structures   show 

more  clearly? 

5.  Crush  the  cells  by  pressure  on  the  cover-glass. 

Note  the  unstained  cell-walls,  and  the   cell- 
contents  stained  brownish  yellow  with  iodine 
(showing  the  presence  of  protoplasm). 
B.  MOTILE  STAGE  :  Zoospores. 

(These  develop  from  forms  in  the  resting  stage 
that  have  been  in  water  for  a  number  of  hours.) 
Study  tvith  a  high  power.      Observe : 
I.  Larger  motile  forms :  macrozoospores. 

1.  Form :  pear-shaped. 

2.  Color. 

3.  Structure. 

(a)  Thin  colorless  cell-wall. 

(b)  Central  protoplasmic  mass  separated  from 

cell-wall  by  clear  space.  Through  the 
clear  space  delicate  protoplasmic  threads 
extend  from  the  central  mass  to  the 
inner  surface  of  the  cell-wall  (probably 
to  a  thin  layer  of  protoplasm  lining 
the  cell-wall). 

From  the  colorless  apex  of  the  proto- 
plasm two  processes  pass  to  the  pointed 


HuflMATOCOCCUS.  29 

end  of  the  cell-wall.  They  are  con- 
tinued beyond  it  as  rapidly  vibrating 
flagella. 

(c)  Nucleus  (not  visible  in  living  specimen). 

(d)  Chromatophores. 

4.  Movements.     Note : 

(a)  Active  locomotion. 

(b)  The  rotation  of  an  individual  on  its  own 

axis. 

(c)  The  movements  of  the  flagella.     (Try  to 

find  a  specimen  whose  movements  have 
become  so  slow  that  the  flagella  may  be 
seen.) 

5.  Stain  with  iodine.     Look  for  the  flagella. 
Sketch  (X  6). 

II.  Smaller  motile  forms :  microzoospores.     Like  the 
macrozoospores  except  in  regard  to  size  and 
cell-wall,  etc. 
Sketch  (X  6). 

PLEUKOCOCCUS. 

Soak  in  water  for  a  few  hours  pieces  of  bark,  etc., 
that  have  a  green  powdery  coating  or  discolora- 
tion. Remove  some  of  the  green  layer  with  the 
point  of  a  scalpel,  mount  in  ivater,  and  study 
ivith  a  high  power.  Look  for  : 

1.  Nucleus. 

2.  Individuals  multiplying  by  cell-division. 
Sketch. 


PARAMCECIUM. 

Mount  a  small  drop  of  ivater  containing  Para- 
mcecia  under  a  supported  cover-glass.  Examine 
first  with  AA%,  and  observe  where  they  are  most 
quiet  ;  then  study  with  D  2. 

I.  General  Characters. 

1.  Form  :   elongated,  flattened,  slipper-shaped ; 

the  anterior  end  rounded,  the  posterior 
pointed. 

2.  Movements  :  by  means  of  cilia  over  the  entire 

surface. 

3.  On  the  ventral  or  oral  surface    an  oblique 

funnel-shaped  depression  (vestibule)  which 
leads  to  the  mouth.  Note  the  direction  of 
the  cilia  in  the  vestibule. 

4.  A  blind  sac  opening  into  the  vestibule  by  the 

mouth  ;  the  oesophagus. 

5.  At  a  definite  point  posterior  to  the  blind  end 

of  the  oesophagus,  the  anal  spot,  where 
waste  matters  are  at  times  passed  out  from 
the  body. 

II.  Structure. 

1.  Ectoplasm :  the  sharply  defined  outer  layer, 
with  a  delicate  surrounding  membrane,  the 
cuticle. 

30 


PARAMCECIUM.  31 

2.  Entoplasm :  the  more  granular,  inner  portion. 

3.  At  the  base  of  the  vestibule  the  mouth-open- 

ing leads  into  a  blind  pouch,  the  oesophagus, 
through  whose  posterior  wall  the  food 
passes  into  the  entoplasm. 

4.  Food-vacuoles :    spherical  spaces  in  the  ento- 

plasm containing  water  and  food-particles. 

5.  Water-vacuoles. 

6.  Contractile  vacuoles  :  one  near  the  anterior  and 

the  other  near  the  posterior  end.  (Study 
carefully,  and  sketch  in  two  or  three  stages.) 

7.  Nucleus :    an   oval    body   near   the    centre    of 

the  cell   (not  always  visible  in  the  living 
state),  the  macronucleus ;   close  to  this  the 
micronucleus. 
/Sketch  a  Paramcecium,  much  enlarged. 

III.  Movements. 

1.  Currents  in  the  entoplasm :   made  evident  by 

changes  in  the  position  of  the  food-vacuoles 
and  the  water-vacuoles. 

2.  Action  of  the   cilia.     (To  see  the  currents  pro- 

duced by  the  cilia  in  the  surrounding  water 
introduce  under  the  cover-glass  a  small  quan- 
tity of  powdered  carmine. ) 

Make  a  diagram  of  the  animal,  and  indicate  by 
means  of  arrows  the  course  of  the  currents. 

IV.  Reproduction. 

Sketch  any  specimens  you  may  find  dividing  by 
fission  or  conjugating. 


32  GENERAL  BIO  LOOT. 

V.  Chemical  Experiments. 

Treat   with   2  per  cent,   acetic   acid;   observe: 
macronucleus,    micronucleus,    and    tricho- 
cysts. 
To  see  the  cilia,  treat  with  dilute  iodine. 


VORTICELLA. 

Mount  in  water  a  fragment  of  a  submerged  leaf  or 
other  substance  to  which  vorticelloe  are  attached. 
Examine  first  with  AA  2.  Observe  form  and 
movements.  Look  for  a  quiet  specimen  and  study 
with  D  2.  When  it  is  extended,  observe  : 

General  Characters. 

1.  Form  :    bell-shaped.     The  bell  attached   by 

its  smaller  end  to  a  stalk. 

2.  Parts: 

(a)  The  conspicuous  rim,  the  peristome,  sur- 

rounding : 

(b)  The  disk  :  which  closes  the  mouth  of  the 

bell. 

(c)  Part  of  the  disk  raised  above   the  peri- 

stome at  one  side,  the  epistome. 

(d)  Cilia  :   bordering   the    peristome  and  the 

epistome. 

(e)  A  space  between  the   peristome  and  the 

epistome,  the  vestibule. 

(/)  The  mouth :  opening  from  the  vestibule 
into  : 

(g)  The  oesophagus. 

(h)  A  definite  region  of  the  vestibule,  the 
anal  spot,  through  which  waste  matter  is 
passed  out  from  the  body  (visible  only  at 
the  time  of  passing  out  of  waste  matter). 

33 


34  GENERAL  BIOLOGY. 

II.  Structure. 

1.  The   thin    transparent    external    layer,    the 

cuticle. 

2.  The   finely  granular  layer  next  to  the  cuticle, 

the  ectoplasm. 

3.  The  central  portion,  the  entoplasm. 

4.  Food-vacuoles. 

5.  Water- vacuoles. 

6.  The  contractile  vacuole  :  generally  situated  near 

the  disk. 

7.  The   nucleus :    a   long   slender    curved    body 

(not  always  visible  in  the  living  specimen). 

8.  The   stalk:   by  which  the  bell   is   attached, 

consisting  of : 

(a)  An  outer   transparent   sheath  continuous 

with  the  cuticle  of  the  bell. 

(b)  The   contractile    axial  filament,    the    pro- 

longation of  the  ectoplasm  of  the  bell. 
Make  a  diagrammatic  sketch  much  enlarged. 

III.  Movements. 

1.  Of  the  cilia. 

Note  the  way  in  which  the  cilia  move,  the 
currents  produced  in  the  water  (to  see 
this  draw  a  few  particles  of  finely  pow- 
dered carmine  under  the  cover-glass),  the 
whirling  of  the  carmine  particles  down 
the  oesophagus. 

2.  Of    the    entoplasm :    made   evident    by   the 

carrying  around  of  food-vacuoles,  etc. 


VORTIGELLA.  35 

3.  Of  the  animal  as  a  whole. 

(a)  Method   of   contraction   of  stalk   and   of 

disk. 

(b)  Mode  of  extension  of  contracted  animal. 
Make  a  diagram   of  an  expanded  and  of  a  con- 
tracted animal  and  label  corresponding  parts. 

Make  diagrams  of  stalk  (a)  in  extended  state ; 

(b)  when  contracted. 
IV.  Reproduction. 
Search  for  : 

1.  Specimens  dividing  by  fission. 

2.  Motile  forms.     When  found  study  with   D  2. 

Observe  the  secondary  band  of  cilia.    Look 
for  the  contractile  vacuole. 

3.  Conjugation :    the    union   of    a   small    motile 

individual  with  a  larger  sedentary  form. 
Y.   Chemical  Experiment. 

1.  Stain  with  iodine  ;  record  the  result. 


YEAST. 

SACCHAROMYCES  CEREVISIJE. 

Put  upon  a  slide  a  drop  of  liquid  that  contains 
actively  growing  yeast  (e.g.  brewer's  yeast  or 
compressed  yeast  in  Pasteur's  fluid],  cover  and 
examine,  with  a  low  power.  Note  : 

I.  General  Characters. 

1.  Aggregations  of  cells  into  groups. 

2.  In  the  larger  individuals  protuberances  par- 

tially constricted  off,  buds. 
Study  ivitli  a  high  power,  and  observe  : 

3.  Form. 

4.  Mode  of  union. 

5.  Size.     (Measure.) 

II.  Structure. 

1.  Cell-wall. 

2.  Cell-contents. 

(a)  Protoplasm    (cytoplasm) :    granular,    with 

shining  spherules. 

(b)  Nucleus  (not   visible  in   the    living  state. 

See   demonstration  of  prepared   speci- 
men*). 

(c)  Yacuoles :  note  the  number  and  size. 
Sketch  (X  10). 

*  For  methods  of  staining,    etc.,    see  "General  Biology,"  by 
Sedgwick  and  Wilson,  second  edition,  1895,  p.  219. 

36 


YEAST.  37 

III.  Reproduction. 

1.  Soiv  a  few  cells  of  freshly  moistened  compressed 

yeast  in  a  few  drops  of  Pasteur's  fluid  on  a 

slide.     Cover,  and  examine  with  a  high  power. 

Compare  the  structure  of  the  cells  with  that 

of  growing  yeast. 
Sketch. 

Put  the  slide  on  a  zinc  rack,  stand  the  rack  in  a 
dish  containing  half  an  inch  of  water,  and  cover 
with  a  bell-jar  (inoist  chamber). 
Examine  from  day  to  day  to  see  multiplication 
by  budding.     (Gemmation.) 

2.  Examine  with  a  high  power  yeast-cells  in  which 

ascospores  have  been  formed.    (Endogenous 
Division.) 
Sketch. 

IV.  Chemical  Experiments. 

1.  Mount  in   water  on    a    slide   a    very    small 

amount  of  powdered  starch.  Look  at  it  with 
a  low  power.  Draw  iodine  solution  under 
the  cover-glass.  Look  again ;  note  the 
effect  of  iodine  solution  upon  starch. 

2.  In  the  same  way  treat  yeast  upon  the  slide 

with  iodine.  What  inference  is  to  be 
drawn  as  to  the  presence  of  starch  loithin 
the  yeast-cell  ? 

3.  Treat  another  specimen  of  yeast  with  magenta 

solution.  What  parts  of  the  yeast  plant  are 
stained  ? 


38  GENERAL  BIOLOGY. 

4.  Crush  the  cells  stained  with  magenta  by  press- 
ing forcibly  on  the  cover-glass  with  the 
handle  of  scalpel  or  needle-holder.  What 
details  of  structure  (see  above,  II.  1  and  2) 
are  visible  after  crushing  ?  Does  the  ma- 
genta affect  all  parts  of  the  cell  equally  ? 
Y.  Physiology. 

1.  Put  a  large  drop  of  yeast  into  each  of  three 

test-tubes  (previously  labelled)  containing 

(a)  Distilled  water  ; 

(b)  Pasteur's  fluid  without  sugar  ; 

(c)  Pasteur's  fluid  with  sugar. 

Stop  the  tubes  with  cotton  and  keep  side  by 
side.  Examine  the  tubes  from  day  to  day 
with  the  naked  eye.  Record  the  result  and 
explain. 

2.  Put  a  drop  of  yeast  into  each  of  two  test-tubes 

of  the  same  size  (previously  labelled)  con- 
taining equal  amounts  of  Pasteur's  fluid 
with  sugar.  Stop  both  well  with  cotton. 
Boil  one  for  five  minutes.  Keep  them  side 
by  side.  Examine  the  tubes  with  the  naked 
eye  from  day  to  day.  Record  the  result 
and  the  explanation. 


PENICILLIUM. 

Observe  Penicillium  growing  upon  bread  in  a  moist 
aim  osphere.  *  Note  : 

I.  General  Characters. 

Velvety-looking  surface,  —  white  in  young 
specimens,  —  dull  bluish  green  in  older 
stages. 

Touch  a  mass  of  Penicillium  spores  ivith  a  needle- 
point,  and  dip  the  needle-point  into  a  drop 
of  water  upon  a  slide.  Cover,  and  examine 
with  a  low  and  then  ivith  a  high  power. 
Note : 

Size.     (Measure.) 
Form. 

In  the  same  way  sow  some  spores  in  Pasteur's 
fluid  in  a  watch-glass.  Put  the  watch-glass  into 
a  moist  chamber.  With  a  hand -lens  watch 
the  development  of  the  mycelium  from  day  to 
day. 

II.  Structure. 

Examine  germinating  spores  (sown  twenty-four 
hours  previously  in  a  vessel  of  Pasteur's  fluid). 

Observe  and  sketch  a  series  of  stages  in  the  germina- 
tion of  the  spores,  noting : 

*  To  obtain  Penicillium,  keep  a  cut  lemon  for  a  few  days  in  a 
moist  atmosphere. 

39 


40  GENERAL  BIOLOGY. 

1.  Formation  of  hyphae. 

(a)  Cell-wall. 

(b)  Protoplasm. 

(c)  Vacuoles. 

(d)  Fat-drops. 

Mount  in  water  a  portion  of  mycelium  from  bread. 
Observe  : 

2.  Hyphse. 

(a)  Division  into  cells. 

(b)  Mode  of  branching.     From  what  part  of 

a  cell  does  a  branch  arise  ? 

(c)  Vacuoles. 
Sketch. 

III.  Keproduction. 

Aerial  hyphse  and  conidiophores. 
Tease  out  in  ivater  some  of  the  mycelium  from  a 
specimen  that   has  become   only  slightly   green. 
Observe : 
1.  Erect  hyphse,  each  consisting  of : 

(a)  Primary  erect  hypha. 

(b)  Branches.     (Terminal   branches :   basidia 

or  sterigmata.) 

(c)  Constrictions  of  the  terminal  branches : 

spores  (conidia).     At  which  end  of  the 
chain    are    the    conidia    larger?       At 
which  end  are  they  first  formed  ? 
Sketch. 


LICHEN. 

I.  External  Characters. 

Examine  ivith  the  naked  eye  the  thallus  of  a  green 
foliaceous  lichen — e.g.,  Parmelia — that  has  been 
moistened  tuith  loater  for  several  hours.  Observe : 

1.  Form. 

2.  Color. 
Sketch  afeiv  lobes. 

With  a  scalpel  carefully  separate  part  of  a  thallus 
from  the  substratum.      Observe : 

3.  The  difference  in  color  between  the  two  sides. 
Place  the  specimen  uncovered  on  a  slide,  the  lower 

surface   uppermost,  and  examine  with  AA  2  by 
reflected  light.      Observe: 

4.  Ehizoids.     (Many  will  have  been  broken  off 

and  only  their  bases  will  show.) 

II.  Structure. 
1.  Sections. 

With  a  razor  make  sections  through  the  thick  part 
of  a  thallus  ;  or,  the  specimen  may  be  rolled  up 
closely  and,  cross -sections  of  the  roll  may  be  made. 
Mount  (in  ivater)  so  as  to  shoiv  the  cut  surface. 
Examine  with  A  A  2  in  strong  reflected  light 
Observe : 

(a)  A  thin  white  superficial  layer :  the  upper 

cortical  layer. 

(b)  A  green  layer  :  gonidial  layer. 

41 


42  GENERAL  BIOLOGY. 

(c)  A    thick,    pure    white    layer :    medullary 

layer. 

(d)  A    dark-colored,    external    layer :     lower 

cortical  layer. 

Sketch. 

2.  Place  a  small  piece  of  the  thallus  in  water  on  a 
slide  and  tear  it  apart  ivith  needles  as  com- 
pletely as  possible.  Cover  and  examine  ivith 
D  2.  Observe : 

(a)  The  hyphse.     Disregard  the  broken  frag- 

ments and  search  for  specimens  in  their 
natural  condition. 

(b)  The  gonidia.     Observe :     . 

Cell  wall. 

Chlorophyll. 

Nucleus  (not  always  visible). 
Sketch  a  few  hyphse  and  gonidia  to  show  their 
form,  their  relative   size,  and  the  manner  in 
which  they  are  connected. 


MUSHROOM. 

I.  External  Characters. 

Note': 

1.  The  vertical  stalk,  or  stipe. 

2.  The  umbrella-like  cap,  the  pileus. 

3.  The  ring,   or  annulus,  around  the  stalk,  the 

remains  of  the  membrane,  the  velum,  con- 
necting the  pileus  with  the  stipe  and  torn 
by  the  extension  of  the  pileus. 

4.  The  underground  mycelium  from  which  the 

stipe  arises. 

5.  On  the  lower  surface  of  the  pileus  radiating 

vertical  plates  or  lamellae. 
Sketch. 

II.  Structure. 

Tease  out  in  ivater  a  piece  of  the  stalk. 

1.  Note  the  hyphge  of  which  it  is  composed. 
Sketch. 

Examine   under  the  low  poiver  the   surface   of  a 
lamella. 

2.  Note    the    spores ;    sometimes  in  groups  of, 

four. 

Cut  in  pith  cross-sections  of  a  lamella. 
Note: 

3.  The  centre  of  the  lamella,  made  up  of  hyphae 

running  parallel  to  the  surface. 

43. 


44  GENERAL  BIOLOGY. 

4.  The   surface   of    the    lamella    consisting   of 

hyphse  at  right  angles  to  the  surface. 

5.  The  swollen  ends  of  many  of  the  hyphse  bear 

four  small  awl-like  points,  the  sterigmata, 

each  with  a  single  spore. 
Sketch. 

Tease   out    in    water    some    of   the   underground 
mycelium. 

6.  Note  the  hyphae. 
Sketch. 


BACTKRIA. 

PRELIMINARY. 

Mix  some  India  ink  or  jmely  powdered  gam- 
boge with  water  and  examine  a  drop  with  a 
high  power. 

Note  that  when  the  currents  in  the  water  have 
ceased  the  particles  of  gamboge  do  not  move 
from  place  to  place. 

Now  observe  the  vibration  or  oscillation  of  the 
lifeless  particles  (Brownian  movement). 

BACTERIA. 

I.  Active  Bacteria. 

Examine  with  the  highest  power  a  drop  of  hay 
infusion  or  of  other  liquid  containing  active 
'bacteria.  Observe  : 

1.  Form. 

2.  Size.    (Measure). 

3.  Structure.     ( What  points  of  structure  are  vis- 

ible ?) 

4.  Movements. 

(a)  Brownian  movement. 

(b)  Active  movement  from  place  to  place. 
Treat  with  iodine. 

Does  the  iodine  bring  out  any  details  of 
structure.  What  is  its  effect  upon  the 
movements  of  the  bacteria? 

45 


46  GENERAL  BIOLOGY. 

II.  Resting  Bacteria — Zooglsea  Stage. 

Examine  the  scum  (zodglcea)  from  the  surface  of 
hay  or  of  other  infusions,  or  of  aquaria,  etc. 
Observe  : 

The    multitudes   of   motionless   bacteria    im- 
bedded in  a  gelatinous  substance. 

III.  Cover-glass  Preparation. 

With  the  forceps  hold  a  perfectly  clean  cover-glass 
nearly  horizontal  and  bring  its  lower  side  just 
into  contact  with  the  surface  of  the  liquid  con- 
taining bacteria  (the  best  results  are  from  a 
scum  that  is  only  just  visible).  Put  the  cover - 
glass,  wet  side  uppermost,  on  a  piece  of  filter- 
paper  slightly  inclined  in  order  that  the  water 
may  drain  off.  When  the  cover-glass  is  dry, 
pass  it  quickly  three  times  through  a  flame  y 
put  a  drop  of  methyl  violet  upon  the  cover- 
glass  j  after  three  or  four  minutes  rinse  off 
with  distilled  water;  invert  the  cover-glass 
upon  a  drop  of  water  on  a  slide  and  examine 
with  a  high  power.  Observe  : 
The  deeply  stained  bacteria. 
The  differences  in  form  and  size. 

Sketch  a  few  of  each  form. 
IY.  Experiments. 

1 .  Clean  a  potato  thoroughly,  sterilize  it  in  steam 
for  an  hour,  and  cut  it  lengthwise  into  halves 
with  a  knife  sterilized  in  the  flame  of 
a  Bunsen  burner.  Put  the  halves  on  a 


BACTERIA.  47 

sterilized  glass  plate  and  expose  the  cut  sur- 
face to  the  air  for  an  hour.  A.t  the  end  of 
this  time  cover  with  a  hell-jar  that  has  been 
sterilized,  and  put  under  this  some  (steril- 
ized) liquid  to  make  a  moist  atmosphere. 

Examine  from  day  to  day  for  ten  days  or 

two  weeks.    Record  results  and  explanation. 

Put   some   freshly-made   hay   infusion   into 

e/  «/  *7  t/ 

three  (previously  labelled)  test-tubes  (a),  (b), 
(c).    Stop  them  securely  with  cotton. 

(a)  To  be  set  aside. 

(b)  To  be  boiled  once  for  3-5  minutes. 

(c)  To  be  boiled  for  3—5  minutes  three  or 

four  times  at  intervals  of  nine  or 
ten  hours. 

Keep  all  three  side  by  side.  Watch  carefully 
for  any  changes  that  may  appear.  Describe 
briefly,  with  explanation. 


SPIROGYRA.* 

I.  General  Characters. 

Observe  with  the  naked  eye.    Note : 

1.  Floating  masses  consisting  of  long,  fine,  green 

threads. 
Take  between  the  fingers  and  note  the  smooth, 

slippery  feeling. 
J^fount  a  small  quantity ,  in  water  on  a  slide ,  cover , 

and  examine  with  a  low  power.     Note : 

2.  Unbranched  filaments. 

(a)  The  shape  of  the  cells. 

(b)  The  way  in  which  they  are  joined. 

(c)  The    difference   between    the    terminal 

cell  and  the  other  cells  of  the   fila- 
ment. 
With  a  high  power  observe  : 

3.  The  form  of  the  cells  composing  the  filament. 

Focus   carefully  and  determine  what  geo- 
metrical form  the  cell  most  resembles. 

II.  Structure. 

With  D  2  examine  : 

1.  The  cell-wall,    (Which  part  is  common  to  two 

cells  ?) 

2.  The  protoplasm. 

*  Spirogyra  can  often  be  found   in   slowly-running  streams  or 
floating  in  the  water  of  quiet  pools. 

48 


SP1ROGTRA.  49 

(a)  Thin  colorless  layer  lining  the  cell-wall, 

primordial  utricle. 
To  see  the  primordial  utricle  better,  treat  with  5 

per  cent,  or  10  per  cent,  salt  solution.      Watch 

carefully  and  observe : 
The  contraction  of  the  primordial  utricle  away 

from  the  cell-wall  (Plasmolysis).     Sketch. 
With  afresh  specimen  observe : 

(b)  One   or   more   green    bands,   generally 

with  jagged  edges,  imbedded  in  the 
primordial  utricle :  the  chromato- 
phore. 

Changing  the  focus  slowly,  follow  the  band  from 
one  end  of  the  cell  to  the  other. 

What  is  its  length  compared  with  that 
of  the  cell  ?     How  is  it  arranged  ? 

(c)  Biconvex    disk-shaped    bodies    in    the 

chromatophore  :  pyrenoids. 

(d)  Near  the  centre  of  the  cell  a  small  mass 

of  protoplasm  suspended  by  fine 
threads  that  connect  it  with  the  pro- 
toplasm lining  the  cell-wall ;  in  its 
centre  is  the  nucleus,  with  a  large 
nucleolus  (not  always  visible  in  the 
unstained  specimen). 

3.  Enclosed  by  the  primordial  utricle  and  oc- 
cupying most  of  the  cell-cavity  :  a  large 
vacuole. 


50  GENERAL  BIOLOGY. 

Sketch  a  complete  cell  with  half  of  each  adjacent 
cell(X  5). 

Stain  slightly  with  iodine  and  carefully  re-examine 
the  cell-structures. 

Look  again  at  the  different  structures  of  the  cell 
in  preserved  specimens  stained  with  borax  car- 
mine* 
I.  Reproduction. 

Mount  in  water  a  group  of  filaments  of  conjugating 
spirogyra.     Examine  with  D  2. 

[There  may  be  present  several  species  of  Spi- 
rogyra— differing  in  the  number  of  the  chro- 
matophores.  In  addition  to  Spirogyra  other 
closely  related  forms  may  also  be  present, — 
asMesocarpus  and  Zygnema, — differing  chiefly 
in  the  size  of  the  filament  and  in  the  shape 
of  the  chromatophore.] 

Search  for  a  series  of  forms  to  show  the  differ- 
ent stages  in  the  process  of  conjugation. 

Observe  the  zygospores:  large  and  oval.  [Those 
of  Zygnema  smaller  and  more  rounded.] 

In  perfect  specimens  each  filament  containing 
zygospores  is  connected  with  a  filament  with 
empty  compartments.  Find  cells  whose  walls 
have  just  begun  to  send  out  a  projection  from 


*  To  preserve  Spirogyra,  put  it  into  a  saturated  aqueous  solution 
of  picric  acid  for  12  hours.  Wash  for  an  equal  length  of  time  in 
water.  Stain  for  some  hours  in  borax  carmine. 


SPIROGYRA.  51 

the  side.     What  is  the  relation  between  the 
condition  of  the  cell-contents  and  the  presence 
or  absence  of  connecting  tubules  between  two 
filaments  ? 
Sketch  a  series  of  stages. 


HYDRA, 

General  Characters. 

Look  at  hydras  in  an  aquarium.     Observe  that 

they  are   found   in   greatest  number   on  the 

illuminated  side.     Notice : 

1.  Form. 

2.  Color. 

3.  Movements. 

With  a  glass  tube  transfer  one  or  more  specimens 
to  a  ivatch-glass ;  place  this  on  white  paper 
and  examine  the  hydra  with  a  hand -lens. 
Observe : 

4.  The  body :  cylindrical  and  varying  in  length 

and  thickness  with  the  degree  of  extension 
of  the  hydra. 
The  parts  of  the  body : 

(a)  The    basal  part,  the  foot,  by  which   the 

animal  adheres  to  foreign  surfaces. 

(b)  The  conical  free  end,  the  hypostome. 

(c)  The  opening  at  the  summit  of  the  hypo- 

stome, the  mouth. 

5.  Highly  contractile  processes  of  the  body-wall 

arranged  around  the  mouth,  the  tentacles. 
Count  them. 

Note  the  symmetrical    arrangement   of    the 
tentacles  around  the  mouth — an  instance  of 

52 


HYDRA.  53 

radial  symmetry  (the  arrangement  of  "  like 
parts  about  an  axis  from  which  they  ra- 
diate "). 

6.  Buds.     (Often  present.) 
Make  simple  outline  sketches  of  the  hydra  when 

extended  and  when  contracted. 
II.  Structure. 

Transfer  ~by  means  of  a  pipette  to  a  slide  and 
mount  in  water,  supporting  the  cover-glass  at 
each  side  ~by  another  cover-glass.  Study  with 
AA  2. 

Review  the  parts  examined  with  a  hand-lens. 
Observe  also  : 

1.  The    transparent  colorless   outer   layer,    the 

ectoderm. 

2.  The  inner  thicker  layer,  the  entoderm*  (green 

in  H.  viridis). 

With  D  2  examine  the  character  of  the  ectoderm 
(best  seen  in  extended  tentacles).  Find  : 

3.  The    knob-like    prominences,  the    nettle-bat- 

teries, f   consisting  of    numerous  cnidoblasts 
(parent-cells  of  nematocysts),  each  with  a  stiff 
projecting  process,  cnidocil. 
Each  cnidoblast  contains  a  highly  refractive 
body  enclosing  a  thread  (nematocyst). 
Kinds  of  nematocysts : 

*  The  green  hydra  shows  best  the  distinction  between  ectodermal 
and  entodermal  cells,  especially  when  macerated. 
\  Best  seen  in  the  brown  hydra. 


54:  GENERAL  BIOLOGY. 

(a)  Large,  often  occupying  the  centre  of  the 

nettle-battery. 

(b)  Smaller   and  more   numerous,   surround- 

ing (a). 

When  a  tentacle  is  in  focus  under  A  A  2,  draw  a 
few  drops  of  magenta  under  the  cover-glass. 
Observe : 

The  discharge  of  the  threads. 
With  D  2  find  the  threads,  and  also  note  in 
the  surrounding  water  discharged  nemato- 
cysts. 

(a)  The  larger  rounded  cysts  do  not  become 

colored. 
Note: 

The  barbs. 

The  long  finely  tapering  thread. 

(b)  The     smaller     oval     nematocysts     stain 

deeply.     Note : 

The  shorter,  thicker  thread. 
Sketch  both  kinds  of  nematocysts. 
III.  Histology. 
A.  Isolated  Cells. 

Tease  out  in  dilute  glycerine  a  hydra  that  has 
been  macerated  and  slightly  stained.*  Examine 
the  fragments  with  the  highest  power  in  a  strong 

*  To  macerate,  put  for  a  few  minutes  into  a  mixture  of  glacial 
acetic  acid  1  part,  glycerine  1  part,  water  2-4  parts  (the  method 
of  Bela  Haller),  and  stain  in  an  aqueous  solution  of  methyl- 
green. 


HYDRA.  55 

light.    Search  for  the  following  kinds  of  cells,  and 
sketch  those  clearly  observed  : 

1.  Entoderm-cells,    of   very   transparent   proto- 

plasm, containing  in  H.  viridis  numbers  of 
Zoochlorella  cells. 

2.  Interstitial    cells :    small    angular    granular 

cells  with  distinct  nuclei  : 

3.  Cnidoblasts    containing    nematoeysts ;    look 

for  the  cnidocil  and  the  nucleus. 

4.  Large  ectoderm-cells  :    pale  cells  with  large 

nuclei ;  the  bases  drawn  out  into  muscular 
processes. 

5.  Nerve-cells  :   small  granular  cells  with  long 

branches  and  distinct  nuclei. 

6.  Gland  -  cells    (entodermal)  :    columnar    cells 

with  distinct  nuclei  and  foam-like,  granu- 
lar protoplasm. 
B.  Prepared  Sections.* 

With  AA  2  observe  in  transverse  section  : 

1.  General  form. 

2.  Ectoderm. 

3.  Entoderm. 

4.  Supporting  lamella. 

*  For  sections  the  hydras  may  be  immobilized  in  a  .25  per  cent, 
aqueous  solution  of  hydroxylamin  in  from  fifteen  to  sixty  min- 
utes, and  then  preserved  in  picro-acetic  acid  ;  or  they  may  be 
killed  instantly  in  the  extended  state  in  a  few  drops  of  water  in 
a  watch-glass  by  pouring  upon  them  hot,  saturated  aqueous  solu- 
tion of  corrosive  sublimate.  Fine  preparations  may  also  be  made 
fiom  hvdras  preserved  in  osmic  acid. 


56  GENERAL  BIOLOGY. 

Make   an  outline   sketch   of  the   section,  omitting 
cell-details. 
With  D  2  study  the  cell-structures  as  far  as 

they  can  be  made  out. 
In  the  ectoderm : 

(a)  Large  vacuolated  ectoderm-cells ;  the  nu- 

clei can  be  seen  in  some  sections. 

(b)  Between  the  large  ectoderm-cells  rows  of 

smaller  deeply  stained  cells,  the  inter- 
stitial cells.  Many  of  these  are  devel- 
oping into : 

(c)  Cnidoblasts. 

(d)  A  row  of  minute  bodies  like  dots  lying 

along  the  outer  side  of  the  support- 
ing lamella :  sections  of  the  contractile 
processes  of  the  large  ectoderm-cells. 

Between  ectoderm  and  entoderm  the  thin, 
structureless,  supporting  lamella. 

In  the  entoderm  : 

(e)  A  single  layer  of  large,  much  vacuolated 

cells.     (What  is  the  explanation  of  the 
appearance  in  the    section  of   several 
layers  of  cells  ?) 
(/)  Small    gland-cells    among    the    ordinary 

entodermal  cells. 
/Sketch  accurately  part  of  the  section  a  few  cells  in 

width. 
Longitudinal  Section. 


HYDRA.  57 

Note  the  central  cavity  enclosed  by  a  wall 
consisting   of  two  layers   separated  by  a 
lamella. 
Make  a  diagrammatic  sketch. 

Find  again  the  cells  seen  in  transverse  sec- 
tion. 


FRESH-WATER   MUSSEL* 

ANODON. 

A.  General  Characters. 

I.  Bivalve  shell  enclosing  the  animal,  the  valves 

fastened  together  by  a  hinge  along  one — the 

dorsal — side. 

1.  Straight  dorsal  side. 

2.  Curved  ventral  side. 

3.  Anterior  end  wide  and  rounded. 

4.  Posterior  end  narrower  and  more  pointed. 

5.  The  bivalve  shell  bilaterally  symmetrical. 

6.  Concentric  lines,  lines  of  growth  of  the  shell. 
Diagram  ! 

Force  apart  the  valves  of  the  shell  about  half  an 
inch  and  insert  a  loedge.     Find : 

7.  The  mantle,  lining  each  valve  of  the  shell. 
With  the  handle  of  a  scalpel  separate  the  mantle 

from  the  right  valve.     Find : 

8.  The  adductor  muscles. 

With  a  strong  scalpel   cut  through  the  attachment 
of  the   muscles   on    the  right  side  close   to   the 

*  Living  mussels  are  advertised  by  some  of  the  dealers  in  Jabo 
ratory  supplies.  For  preservation  they  should  be  put  for  twenty- 
four  hours  into  70  per  cent,  alcohol  (which  is  reduced  to  a  much 
lower  per  cent,  by  the  water  inside  the  shell),  then  changed  to  70 
per  cent,  alcohol  for  twenty-four  hours,  and  kept  permanently  in 
80  per  cent,  alcohol. 

58 


FRESH-WATER  MUSSEL.  59 

shell.     Remove  the   right   valve.     On  Us   inner 
surface  find: 
9.  The  Hue  of  attachment  of  mantle  to  shell. 

10.  Impressions  of  muscle-attachments. 
Near  the  anterior  end : 

(a)  A  large  impression  made  by  the  anterior 

adductor  and  the  anterior  retractor  mus- 
cles. 

(b)  A. small  impression  near'(a),  that  of  the 

protractor  muscle. 
Near  the  posterior  end : 

(c)  A  large  impression,  of  the  posterior  adduc- 

tor and  the  posterior  retractor  muscles. 
As  the  mussel  lies  on  the  left  valve,  find : 

11.  The   muscles  whose  impressions   have  been 

seen  in  10.     Observe  : 

12.  The  mantle  enclosing  the  other  parts  of  the 

animal. 

13.  The  edges  of  the  mantle  closely  applied  ex- 

cept at  the  posterior  extremity,  where  they 
separate  to  leave  two  orifices ; 

(a)  A  smaller  dorsal  opening  (through  which 
water  passes  out),  the  exhalent  aperture. 

(b)  A  larger  opening  more  ventral   (through 

which  water  enters),  the  inhalent  aperture. 
Diagram  ! 

Insert  a  bristle  into  each  opening,  and  tlien  raising 
the  flap  of  the  mantle  see  : 

14.  Inserted  into  the  more   ventral    opening    it 


60  GENERAL  BIOLOGY. 

passes  into  tlie  space  between  the  flaps  of 
the  mantle,  the  pallia!  or  mantle-cavity. 

15.  Inserted  into  the  dorsal  opening  it  enters  the 

cloacal  chamber  and  passing  forward  enters 
the  mantle-cavity. 

In  the  mantle-cavity  find  the  following  struc- 
tures : 

16.  Inside  of  the  mantle  on  each  side  two  gills  or 

branchiae. 

17.  Projecting  ventrally  near  the  anterior  end, 

the   thick   foot,   continued    dorsally   as  the 
visceral  mass. 

18.  Attached  to  the  mantle  anterior  to  the  gills 

two    triangular   folds    on    each    side,    the 
labial  palps. 

The  gills,  the  foot,  and  the  labial  palps  all 
hang  down  in  the  mantle-cavity.  By  the 
union  of  the  inner  gills  in  the  posterior 
median  line  a  partition  is  formed  that 
divides  the  posterior  part  of  the  man  tie - 
cavity  into  two  : 

The  large  ventral  branchial  chamber. 

The  smaller  dorsal  suprabranchial  chamber. 

The   posterior  end  of  this  forms  the  cloacal 

chamber. 
Pass   a   bristle  again    into    the   cloacal  chamber, 

through  the  suprabranchial  chamber,   and   into 

the  branchial  chamber. 


FRESH- WATER  MUSSEL.  61 

II.  External  Openings. 

1.  The  labial  palps  are  united  at  their  bases  to 

form  ridge-like  anterior  and  posterior  lips. 
Between  these  is  the  mouth. 

2.  On  either  side  of  the  visceral  mass  near  the 

attachment  of  the  gills  is  a  small  genital 
opening. 

3.  Close  to  2,  slightly  more  dorsal,  is  the  ex- 

cretory opening. 

4.  On  the  dorsal  side  of  the  cloacal  chamber 

close  to  its  external  opening  is  the  anus. 
Make  a  diagram  of  the  animal  as  it  would  be  seen  if 

the  mantle-flap  of  one  side  were  absent. 
B.  Anatomy. 
I.  Circulatory  System. 

On  the  dorsal  side  of  the  body  immediately 
in  front  of  the  posterior  adductor  muscle 
is  the  pericardial  cavity  with  thin  semi- 
transparent  walls. 

Gut  with  fine  scissors  through  the  thin  wall  a  little 
to  the  right  of  the  median  dorsal  line,  taking  care 
not  to  cut  deeper,  thus  exposing  : 

1.  The  pericardial  cavity.     It  contains  : 

2.  The  heart. 

(a)  In  the  median  line  the  opaque,  muscular 

ventricle. 

(b)  Into  the  ventricle  opens  on  each  side  a 

thin-walled  auricle.     The  auricles  are 
funnel-shaped  with  the  narrow  end  at- 


62  GENERAL  BIOLOGY. 

tached  to  the  ventricle  and  the  broader 
end  to  the  dorsal  border  of  the  gills. 
3.  The  vena  cava  running  parallel  to  the  heart 
under  the  floor  of  the  pericardial  cavity  ;  it 
will  be  seen  later  (C.  II.)  in  section. 
Note  the  rectum  passing  posteriorly  from  the 

posterior  end  of  the  heart. 
Make  a  diagram  of  the  heart. 

II.  Excretory  System. 

In  the  anterior  angle  of  the  pericardial  cavity 
on  each  side  is  a  minute  pore,  the  internal 
opening  of  the  excretory  organ,  the  organ 
of  Bojanus,  the  dark  mass  on  each  side 
beneath  the  floor  of  the  pericardial  cavity, 
(For  the  external  opening  of  the  excretory 
organ  see  A.  II.  3.) 

III.  Nervous  System. 

Remove  the  mussel  from  the  shell ,  place  it  dorsal 
side  down,  and  cut  through  the  partition  between 
the  'branchial  and  the  cloacal  chambers.     See : 
1.  Close  to  the  ventral  side  of  the  posterior  ad- 
ductor, the  visceral  or  parieto-splanchnic  gan- 
glion. 

Gently  strip  off  the  thin  skin  covering  the 
ganglion,  and  find  the  chief  nerves  given  off 
from  it : 

(a)  The  posterior  pallial  nerve. 

(b)  The  lateral  pallial  nerve. 

(c)  The  branchial  nerve. 


FRESH- WATER  MUSSEL.  63 

(d)  A  nerve  passing  forward  on  each  side  of 
the  middle  line,  the  cerebro-splanchnic 
commissure.  Trace  one  forward  through 
the  body  to  the  : 

2.  Cerebral   ganglion   of   that   side,  lying   close 

beneath  the  skin  at  the  base  of  the  labial 
palps  immediately  in  front  of  the  protractor 
muscle. 

Find  the  cerebral  ganglion  of  the  other  side, 
and  the  commissure  connecting  the  two 
across  the  mid-line  around  the  dorsal  side 
of  the  mouth. 

3.  Deeply-buried  in  the  foot  along  the  plane  of 

its  junction  with  the  visceral  mass,  the 
pedal  ganglia,  closely  connected  by  a  trans- 
verse commissure. 

They  may  be  found  by  making  with   a   razor  a 

median  vertical  section  of  the  foot,  or  by  following 

the  commissure  from  the  cerebral  ganglion  of  one 

side. 

Find  the  commissures  connecting  pedal  and  cerebral 

ganglia. 

Make  a  diagram  of  the  nervous  system. 
IV.  The  Digestive  System. 

Insert  a  small  blunt   instrument  into  the  mouth. 
With  this  as  a  guide  open  the  alimentary  canal 
ivithjine  scissors.     Observe: 
1.  The  mouth. 


64  GENERAL  BIOLOGY. 

2.  The    oesophagus  ;  a  short  straight  tube   ex- 

tending obliquely  upward  to  : 

3.  The  stomach :  a  dilatation  of  the  alimentary 

canal. 

(The  intestine  passes  with  many  turns  through 
the  visceral  mass,  and  will  be  seen  later  in 
sections.) 

In  ike  same  way  open  the  rectum  frown  the  anus, 
and  trace  its  course  through  the  pericardia! 
cavity. 

Look  for  the  typhlosole. 
V.  The  Gills. 

1.  Take  out  one  of  the  gills,  cut  it  transversely, 

and  examine  the  cut  edge  with  a  hand-lens. 

2.  Examine  with  the  low  and  then  with  the  high 

power  a  small  piece  of  one  lamella. 

3.  In  some  specimens  the  outer  gills  are  dis- 

tended with  young  mussels  (glochidia).     If 
these  can  be  obtained,  mount  and  examine 
with  a  low  and  with  a  high  power. 
C.  Sections. 

Remove  the  shell  from  a  second  specimen,  place 
the  mussel  on  its  side  upon  the  wax  in  a  dis- 
secting-pan,  and  with  a  razor  make  sections  a 
quarter  of  an  inch  thick.  A.rrange  the  sections 
in  order,  fastening  each  in  place  with  a  piny 
and  cover  them  with  water. 
Study  especially  the  following  sections : 


FRESH- WATER  MUSSEL.  65 

I.  Through  the  pedal  ganglia. 

Find  the  stomach,  digestive  gland,  labial  palps, 
foot,  and  mantle. 

II.  Through  the  heart. 

Find  the  ventricle,  the  rectum  with  the  typh- 
losole,  auricles,  organ  of  Bojanus  on  each 
side  with  the  vena  cava  between,  the  vis- 
ceral mass  with  the  intestine  cut  through 
in  a  number  of  places,  the  reproductive 
organ  filling  up  the  greater  part  of  the 
visceral  mass,  the  foot,  the  inner  and  outer 
gills,  the  suprabranchial  chamber  dorsal 
to  the  outer  gill  on  each  side,  the  branchial 
chamber,  the  mantle. 

III.  Through  the  visceral  ganglia. 

Find    the    rectum,    the    posterior   adductor 
muscle,  the  visceral  ganglia,  the  divisions 
of     the     suprabranchial     chamber      (how 
many  ?),  the  branchial  chamber,  the  mantle. 
Diagram  of  these  three  sections  ! 
In  the  other  sections  trace  the  organs  from 
section  to  section. 


LOBSTER.* 

A.  EXTEKNAL  CHARACTERS. 

I.  The  hardened  cuticle,  the  exoskeleton,  covering 

the  animal. 

II.  The  body,  consisting  of: 

1.  An  anterior   part,  the   cephalothorax,  with   a 

firm  continuous  covering  above  (carapace). 
Parts  of  carapace : 

(a)  Cephalic  part,  covering  the  head  of 
the  lobster  ;  prolonged  anteriorly  into 
the  frontal  spine,  on  each  side  of  which 
is  a  depression  containing  the  stalked 
eye  ;  limited  posteriorly  by  the  cervi- 
cal groove  which  separates  it  from  : 
(6)  Thoracic  part,  covering  the  thorax,  con- 
sisting of: 

(aa)  Median  dorsal  part,  separated  by  a 
very  slight  groove  on  each  side, 
the  branchio-cardiac  groove,  from  : 
(bb)  Two  lateral  parts,  one  on  each  side, 
the  branchiostegites,  which  protect 
the  gills. 

*  If  lobsters  cannot  be  obtained  in  the  market,  these  directions 
will  answer  nearly  as  well  for  the  crayfish. 

66 


LOBSTER.  67 

Raise  the  branchiostegites  and  see 

beneath  them  the  gills. 

2.  A  jointed  flexible   posterior  part,  the  abdo- 
men. 

Count   the   number    of   segments.     In    what 
plane    or    planes    can    the    abdomen    be 
moved  ? 
HI.  Appendages. 

Jointed  limbs  attached  to  the  ventral  aspect  of 
the  body.       (To  be  studied  in    detail    later 
(0.  II.) ). 
IV.  External  Openings. 

1.  The  slit-like  auditory  openings :   on  the  flat 

upper  surface  of  the  basal  segments  of  the 
antennules. 

2.  The  excretory  openings,  perforating  a  tuber- 

cle on  the  ventral  side  of  the  basal  segment 
of  each  antenna. 

3.  The    mouth,   in    the   median   line,   seen   by 

pushing  apart  the  appendages  on  the  ven- 
tral side  of  the  head. 

4.  The  genital  openings  : 

(a)  In  the  female :  on  the   basal  segment 

(coxopodite)  of  the  second  from  the 
last  thoracic  appendage. 

(b)  In  the  male .  on  the  basal  segment  of 

the  posterior  thoracic  appendage. 

5.  The  anus :  a  slit  on  the  ventral  surface  of  the 

posterior  abdominal  segment. 


68  GENERAL  BIOLOGY. 

B.  ANATOMY. 

I.  Circulatory  System. 

Gut  ivith  strong  scissors  through  the  two  branchio- 
cardiac  grooves  and  transversely  through  the 
cervical  groove  (taking  great  care  not  to  cut 
through  the  skin  beneath)  and  remove  the  isolated 
part  of  the  carapace. 
Note: 

The  skin,  colored  by  red  pigment. 
Cut  through  the  body -wall  by  a  shalloiu  cut  in  the 
median  line  and  a  transverse  cut  at  each  end  of 
the  median  cut.     Turn  aside  the  flaps,  thus  open- 
ing the  pericardial  sinus  and  exposing : 

1.  The  heart :  pentagonal  and  slightly  yellowish, 

lying  in  the  median  line. 
Find   delicate    strands    of   muscle    that  pass 

from  the  angles  of  the  heart  to  the  wall  of 

the  pericardial  sinus. 
The  heart  receives  blood  from  the  pericardial 

sinus   through    three   pairs    of    valve-like 

openings,  ostia : 

(a)  A  dorsal  pair  :  visible  now. 

(b)  A  lateral   pair :    better   seen    at   a   later 

stage  (B.  I.  2.  (e)). 

(c)  A  ventral  pair  :  better  seen  at  a  later  stage. 

2.  Arteries :  arising  from  the  heart.     (These  are 

extremely  delicate  and  must  be  looked  for 
with  great  care.) 
From  the  anterior  region  of  the  heart : 


LOBSTER.  69 

(a)  A  median  ophthalmic  artery. 

(b)  A  pair  of  antennary  arteries,  close  to  (a), 

one  on  each  side. 

(c)  Posterior   and   ventral   to    (b),  a   pair   of 

hepatic  arteries. 
From  the  posterior  region  of  the  heart : 

(d)  A  large  median  superior  abdominal  artery. 

By  longitudinal  cuts  remove  a  narrow 
piece  of  the  abdominal  exoskeleton  and 
follow  the  artery  through  the  abdomen. 

(e)  Passing  ventrally  from  the  ventral  aspect 

of  the  heart  a  large  median  sternal 
artery :  better  seen  at  a  later  stage. 
(See  below.) 

Diagram  of  heart  and  of  arteries  thus  far  seen. 
Folloiv  out  tliefive  arteries  from  the  anterior  end 
of  the  hearty  as  far  as  possible  tvitJiout  injury  to 
the  other  organs. 

Out  through  the  anterior  arteries,  and  turning 
back  the  heart  find  the  lateral  and  ventral  ostia 
(B.  I.  1.  (b),  (c)),  and  the  sternal  artery  (B,  I. 
2.  (e)). 

Cut  through  the  sternal  artery  close  to  the  heart  and 
through  the  superior  abdominal  artery  and  take 
out  the  heart. 

Finish  diagram  of  the  heart  and  arteries  ! 
II.  Eeproductive  System. 

On  each  side  of  the  heart  and  partly  ventral  to  it, 
find: 


70  GENERAL  BIOLOGY. 

In  the  male : 

1.  The   testes :   two   long,  white,  lobecl   bodies 

which  extend  posteriorly  into  the  abdomen 

and  are  connected  near  their  anterior  ends 

by  a  transverse  commissure. 
Near  the  middle  of  each  testis  a  vas  deferens 

arises  and  passes  ventrally  to  the  genital 

opening  (A.  IV.  4.  (£>).) 

By  cutting  through  the  muscles,  etc.,  at  the  side, 
folloiv  the  vas  deferens  of  one  side  from  the  testis 
to  the  external  opening. 
In  the  female : 

2.  The  ovaries  :  elongated,  yellowish  bodies  con- 

tinued posteriorly  into  the  abdomen,  with 
the  oviduct  passing  to  the  genital  opening 
(A.  IV.  4.  (a)). 
Trace  the  oviduct  from  the  ovary  to  the  external 

opening. 

Diagram  of  reproductive  organs  and  ducts  ! 
III.  Digestive  System. 

In  the  median  line  anterior  to  the  region  of 
the  heart : 

1.  The  stomach  a  dilatation  of  the  alimentary 

canal. 

Insert  the  handle  of  a  section-lifter  through  the 
mouth-opening  into  the  stomach.  Turn  the  stomach 
to  one  side  to  see  : 

2.  The  oesophagus :  a  short  vertical  tube  from 

mouth  to  stomach. 


LOBSTER.  71 

Diagram  of  the  oesophagus  and  stomach  as  they 
would  appear  if  seen  from  the  side.     Observe  : 

3.  Posterior  to  the  stomach  on  each  side  a  large, 

soft,  brown  or  greenish-yellow  structure,  the 
digestive  gland. 

Gently  pushing  it  with  the  handle  of  a  scalpel  away 
from  the  middle  line,  find  : 

4.  The  duct  of  the  digestive  gland  of  that  side, 

a  short,  wide,  thin-walled  tube  which  enters 

the  part  of  the  alimentary  canal,  the  mesen- 

teron,  immediately  posterior  to  the  stomach. 

Removing  tJie  reproductive  organs  and  the  digestive 

gland ,  and  separating  the  muscles  of  the  abdomen 

in  the  median  line,  find  : 

5.  The  intestine  :  a  straight  tube  leading  from 

the  mesenteron  to  the  anus. 
Finish  the  diagram  of  the  digestive  system.  Cut 
with  fine  scissors  through  the  oesophagus  close 
to  the  stomach,  and  through  the  intestine,  and 
take  out  the  stomach.  Open  the  stomach  and  ex- 
amine : 

6.  The  arrangement  of  the  gastric  teeth. 
IV.  Excretory  System. 

In  the  extreme  anterior  part  of  the  cephalic 

cavity  on  each  side. 

1.  Paired,  delicate,  greenish  structures,  the  ex- 
cretory organs  (green  glands). 
(For  the  external  openings  see  A.  IV.  2.) 


72  GENERAL  BIOLOGY. 

Y.  Endophragmal  System. 

Calcified  projections  from  the  inner  side  of 
the  exoskeleton  of  the  ventral  surface  of  the 
thorax  form  an  internal  skeleton — the  endo- 
pliragmal  skeleton,  which  arches  over  a  canal 
— the  sternal  canal. 
To  see  the  endophragmal  system  remove  the  thoracic 

viscera  and  the  muscles  ventral  to  them. 
YI.  Nervous  System. 

Cut  through  the  endophragmal  system  at  each  side 
of  the  median  line,  thus  exposing  the  thoracic 
part  of: 

The  central  nervous  system,  which  runs  the 
whole  length  of  the  body,  in  the  median  line, 
consisting  of  : 

1.  The    supraoesophageal   or   cerebral   ganglia, 

dorsal  to  the  oesophagus.  Each  ganglion 
gives  off  nerves  to  the  eye,  to  the  anten- 
nule,  and  to  the  antenna  of  its  own  side. 

2.  The  circumoesophageal  commissure   passing 

posteriorly  and  ventrally  from  the  cerebral 
ganglia  around  the  oesophagus  to  the  first 
pair  of : 

3.  The  thoracic   ganglia :    six   pairs    united  by 

longitudinal  commissures. 
Follow  the  commissures  passing  posteriorly 
from  the  posterior  pair  of  thoracic  ganglia, 
and  find  in  the  abdomen  : 


LOBSTER.  73 

4.  The  abdominal  ganglia :    six   pairs  likewise 

connected  by  longitudinal  commissures. 
Diagram  of  the  nervous  system  ! 

C.    EXOSKELETON  AND  APPENDAGES   IN    DETAIL. 

I.  Typical  Abdominal  Segment. 

Make,  a  diagram,  of  the  third  abdominal  segment  as 
it  ivould  appear  if  seen  in  anterior  or  posterior 
view,  to  show  the  form  of  the  segment  and  its 
appendages. 

II.  Appendages. 

Take    off  all    the   appendages  from   one  side   of 

the  body,  beginning   at  the  posterior  end,  being 

especially  careful  to  remove  each  appendage  entire. 

Observe  : 

The  appendages  that  bear  the  gills. 

The  gills  that  are  borne  elsewhere. 

Compare  each  different  kind  of  appendage 
with  the  second  maxilliped,  and  by  refer- 
ence to  the  chart  *  determine  the  homolo- 
gous parts  in  the  series. 

Find  the  scaphognathite.  Of  what  parts  is  it 
made  up  ?  In  what  way  can  it  move  ? 

Of  what  parts  is  the  telson  composed  ? 

Diagrams  of  : 

The  third  abdominal  appendage. 

*  Enlarged  from  Plate  VIII,  The  Appendages  of  the  Crayfish, 
in  "The  Atlas  of  Practical  and  Experimental  Biology,"  G.  B. 
Howes. 


74  GENERAL  BIOLOGY. 

The  posterior  thoracic  appendage. 

The  fifth  thoracic  appendage. 

The  fourth  thoracic  appendage. 

The  second  maxilliped. 

The  first  maxilliped. 

The  second  maxilla. 

The  first  maxilla. 

The  mandible. 

The  antenna. 

The  antennule. 


MOSS. 

POLYTRICHUM. 

A.  SEXUAL  GENERATION.     (Oophore.) 
Keeping  the  specimen  moist,  observe  : 

I.  General  Characters. 

1.  Stem  :  erect  and  unbranched  (or  branching 

only  from  the  base). 

2.  Leaves :  pointed  at  one  end.   Attached  to  the 

stem  without  a  stalk  (i.e.,  sessile), 

3.  Rhizoids  :    at  the    base  of  the   stem   (often 

hidden  by  the  sand,  etc.,  clinging  to  them  j 
to  see  them  distinctly,  rinse  in  water). 

4.  Flowering  heads. 

(a)  In  male  flowers  a  terminal  rosette  of  stiff 

green  leaves  (perichsetium)  surrounding 
the  antheridia. 

(b)  In  female  flowers  a  terminal  bud  formed 

by    the    folding    together   of    terminal 
leaves  that  enclose  the  archegonia. 
Sketch. 

II.  Histology. 
1.  Stem. 

Remove  the  leaves  near  the  base  of  the  stem  ;  until 
a  razor  make  a  thin  transverse  section,  mount  in 
water,  and  observe  : 

(a)  The  thin  epidermis  (best  seen  in  young 

75 


76  GENERAL  BIOLOGY. 

specimens),  and  the  subepidermis :  a 
conspicuous  brown  layer. 

(b)  Next  to  this  a  region  of  nearly  colorless 

cells.  Compare  these  with  (a)  in  regard 
to  cell-contents  and  thickness  of  cell- 
wall. 

(c)  In  the  centre  a  central  or  axial  strand. 
Make  a  diagram  showing  the  outlines  of  the  different 

regions.     Sketch  a  few  cells  of  each  kind  to  show 
tlieir  characteristics. 

Make  a  longitudinal  section,  mount  in  ivater  and 
find  the  same  regions.  Sketch  carefully  to  the 
same  scale  a  few  cells  of  each  kind. 

2.  Leaf. 

Mount  in  water  a  young  leaf  of  a  more  delicate 
species  of  moss — as  Mnium — and  study  with  D  2 
to  see  : 

(a)  The  structure,  a  thin  lamina  with  a  thicker 

median  region,  the  midrib. 

(b)  The  margin  of  the  lamina. 

Sketch  two  or  three  cells  at  the  edge  of  the  leaf  to 
show  the  character  of  the  margin. 

3.  Ehizoids. 

Mount  in  water.      With  D  2  note  : 

(a)  Cell-contents. 

(b)  Any  difference  that  is  observable  between 

the  younger  and  the  older  rhizoids. 
Sketch. 

4.  Reproduction. 


MOSS.  77 

A.  Male  Plant.     Sketch. 

With  a  razor  make  longitudinal  sections  of  the 
flowering  head.  Mount  in  ivater  and  observe  at 
the  apex  of  the  axis  within  the  perichcetial  leaves  : 

(a)  Antheridia  :  oblong  sacs  with  a  wall  of  a 

single  layer  of  cells.     Within  the  sacs 
are  mother-cells  of  antherozoids. 

(b)  Filaments  (paraphyses). 

(aa)  Hairlike. 
(bb)  Spatula-shaped. 

Sketch  an  antheridium  from  the  surface  and  in  op- 
tical section. 
Sketch  each  kind  of  paraphysis. 

B.  Female  Plant.     Sketch. 

With  needles  separate  the  leaves  from  the,  top  of  the 
axis  of  the  female  flowering  head  and  search  for: 

(c)  Archegonia  :    flask  -  shaped    bodies    with 

elongated   neck   and    enlarged    ventral 
part  containing  the  oosphere. 

(d)  Paraphyses. 
Sketch. 

B.  ASEXUAL  GENERATION.     (Sporophore.) 

Observe : 
I.  General  Characters. 

1.  The  slender  stalk,  seta,  which  supports  : 

2.  The  capsule,  which  contains  the  spores. 
Sketch. 

The  parts  of  the  capsule  : 

(a)  The  thick  hairy  cap,  calyptra. 


78  GENERAL  BIOLOGY. 

Take  off  the  calyptra  and  by  reflected  light  note 
beneath  it  : 

(b)  The  operculmn. 

Sketch  the  capsule  with  the  calyptra  removed.  Take 
off  the  operculum  and  observe : 

(c)  Around  the  rim  on  which   it  rested,  the 

teeth  of  the  peristome. 

(d)  Stretched  across  between  the  tips  of  the 

teeth,  the  epiphragma  partially  closing 
the  spore-case. 
Divide  the  capsule  transversely  and  make  a  diagram 

of  the  cut  surface. 
Examine  and  sketch  a  spore. 
C.  PKOTONEMA. 

Examine   with  the  naked   eye    some   living  moss- 

protonema* 

Mount  some  of  the  protonema  in  water;  with  needles 
gently  separate  the  green  .filaments;  cover  and 
examine  with  D  2.  Observe : 

1.  The  green  branching   filaments  made  up  of 

cells. 
Sketch. 

2.  Growing  out  in  places   from  the  protonema 

buds  developing  into  moss-plants. 
If  observed,  sketch. 

*  Found  growing  as  a  green  encrustation  on  banks  of  earth 
without  much  other  vegetation,  by  roadsides,  etc.,  in  partly 
shaded  places,  especially  those  exposed  to  the  north. 


SPERMAPHYTES. 

STEM. 

I.  Gymnosperm, 

Make  with  a  razor  thin  sections — transverse,  radial, 
and  tangential — of  pine  wood  that  has  been  soaked 
in  water.     Mount  in  dilute  glycerine  and  study 
with  A  A  2  and  D  2. 
Observe  in  the  transverse  section : 

1.  The  annual  rings. 

Compare  the  two  edges  of  a  ring. 

2.  The  thick-walled  pitted  tracheids. 

3.  The  narrow  medullary  rays. 

Make  a  diagram  with  AA%  showing  the  relation  of 

the  autumn  to  the  spring  ivood,  and  of  the  wood 

to  the  medullary  rays. 
With  D  2   sketch  accurately  a  small  part  of  the 

section. 

In  the  tangential  section  observe  : 

1.  The  tracheids  :  their  form,  their  arrangement, 

and  the  pits  in  their  walls. 

2.  The  medullary  rays. 

Make  a  diagram  showing  the  relation  of  tracheids 

and  medullary  rays. 
Sketch  accurately  with  DZ  a  small  part  of  tht 

section. 

Observe  in  the  radial  section  : 

79 


80  GENERAL  BIOLOGY. 

1.  The  tracheids.    Why  is  a  larger  number  of 

pits  visible  in  this  section  ? 

2.  The  medullary  rays. 

Make  a  diagram  shoiving  tlie  relation  of  tracheids 

and  medullary  rays. 
Sketch  a  few  tracheids  much  enlarged. 

From  what  has  been  seen  in  the  three  sec- 
tions describe  the  shape  of  a  medullary 
ray. 

II.  Angiosperm. 
A.  Dicotyledon. 

Ampelopsis.  Prepared  transverse  section  of 
entire,  young  stem.  Study  with  AA  2  and  D  2. 
AA  2.  Observe  : 

1.  Epidermis,  one  cell-row  in  thickness. 

2.  Cork    (subepidermis)    consisting   of    several 

layers  of  flattened  cells. 

3.  Cortical  parenchyma. 

4.  Fibrovascular  bundles. 

5.  Pith. 

6.  Medullary  rays. 
Diagram. 

Which  tissues  have  cell-contents  ? 

Cut  a  section  from  fresh  material  and  see 

which  tissues  contain  chlorophyll. 
D  2.  In  the  fibrovascular  bundle  observe  the 

cambium    layer    dividing   the   bundle   into 

an  inner  part    (xylem)  and  an  outer  part 

(phloem). 


8PERMAPHYTES.  81 

Xylem,  consisting  of : 

7.  Large  vessels  or  tracheae. 

8.  Tracheids,  smaller  in  cross-section  than  the 

vessels. 

9.  Wood  parenchyma  (?).   Thin-walled  cells  with 

cell-contents. 
Phloem,  consisting  of : 

10.  Sieve-tubes,  thin-walled  and  in  some  places 

showing  the  perforated  ends  of  the  cells. 

11.  Bast-cells,  thick-walled. 

Sketch  accurately  a  feiv  cells  of  each  kind  in  their 

relation  to  one  another. 
B.  Monocotyledon. 

Observe  with  the  naked  eye  the  cut  end  of  a  stem 
of  Indian  corn.     Note  : 

1.  The   firm    outer   layer   (epidermis   and  sub- 

epidermis). 

2.  The  fundamental  parenchyma. 

3.  The  isolated  fibrovascular  bundles. 

Make  thin  cross-sections  through  the  outer  part  of 
the  stem.     Mount  in  dilute  glycerine  and  study 
ivith  A  A  2  and  D  2. 
Observe  in  the  bundles  : 

4.  The  two  large  pitted  tracheids. 

5.  The  smaller,  spiral  and  annular  vessels  (one 

or  more)  between  the  tracheids  and  nearer 
the  centre  of  the  stem.  In  many  instances 
the  cells  immediately  surrounding  these 


82  GENERAL  BIOLOGY. 

vessels  have  disappeared,  leaving  an  irreg- 
ular space. 
6.  The  thin-walled  phloem  on  the  side  opposite 

the  vessels. 

The  prosenchyma  forming  the  outer  part  of 
the  bundle  does  not  belong  to  the  bundle 
itself.  It  is  a  bundle-sheath  of  modified 
fundamental  tissue. 

HOOT. 

Lay  in  water  on  a  slide  the  root  of  a  young  mus- 
tard-seedling grown  in  sawdust.  Cover  and  ex 
amine  with  AA  2. 

1.  Find    the    region    in    which    root-hairs    are 

present. 
Sketch. 

2.  Moisten   a  piece    of   blue  litmus-paper   and 

touch  it  to  the  root  of  a  fresh  specimen. 
Record  the  result. 

3.  Examine   the   root-cap  of  Pontederia  or   of 

Lemna. 
Sketch  under  AA  2. 

BUD. 

Winter  buds  of  elder  or  of  horse-chestnut. 

I.  Sketch  the  ~bud. 

II.  Take  off  the  bud-scales  and  the  undeveloped  leaves 

in  regular  order ',  beginning  with  the  outermost. 
Notice  the  way  in  which  they  overlap. 


8PERMAPHYTES.  83 

III.  Compare  as  to  texture  the  outer  scales  with 

what  is  inside.  Suggest  a  reason  for  the 
difference.  What  other  means  are  there  for 
the  same  purpose  ?  (Make  a  note  of  the 
answers.) 

IV.  Compare  a  closed  bud  with  others  *  in  different 

stages  of  unfolding.     Make  a  note  of  what  is 
observed. 

LEAF. 

I.  Strip  off  some  of  the  epidermis  from  a  hyacinth-leaf. 

Mount  in  water  and  examine  ivith  AA%  and  D  2. 
Observe  : 

1.  The  elongated  cells  of  the  epidermis  without 

chlorophyll.     Compare  with  the  epidermis 
of  the  fern. 

2.  The   stomata,  each  with  two  guard-cells  con- 

taining chlorophyll. 
Sketch  a  few  cells  accurately  (D  2). 

II.  Out  a  transverse  section  of  the  leaf  of  the  india- 

rubber  tree  (Ficus  elastica).     Mount  in  water. 
Draw  accurately. 

Beginning  with  the  upper  surface  find  : 
1.  The  upper  epidermis,   consisting  of  several 

*  Buds  in  different  stages  of  opening  can  be  obtained  at  any 
time  during  the  winter  by  keeping  cut  stems  in  water  for  a  few 
weeks.  Flowering  branches  with  the  flower  in  different  stages 
of  unfolding  should  be  preserved  in  alcohol  from  the  previous 
season. 


84  GENERAL  BIOLOGY. 

layers  of  thick-walled  cells  without  chloro- 
phyll. Compare  with  the  epidermis  of  the 
ferD. 

2.  Elongated  cells  closely  packed  together,  with 

their  long  diameter  at  right  angles  to  the 
surface  of  the  leaf,  the  palisade  tissue,  con- 
taining many  chlorophyll-bodies. 

3.  Other  cells  containing  chlorophyll,  somewhat 

irregular  in  shape  and  loosely  arranged, 
so  that  between  them  are  large  open 
spaces,  intercellular  spaces. 

4.  The  veins,  fibrovascular  bundles,  cut  trans- 

versely or  obliquely. 

5.  The  lower  epidermis,   much  like  the  upper, 

but  with  stomata  at  intervals. 
What  is  the  relation  between  the  position  of 
the  stomata  and  the  intercellular  spaces  ? 

FLOWER. 
Geranium. 

I.  The  General  Structure. 

(a)  Borne  on  a  short  stalk  (pedicel). 
(6)  Composed    of    four    rows    or    whorls    of 
organs. 

1.  The  external  green  calyx. 

2.  Inside  the  calyx  the  corolla,  the  most  conspic- 

uous  part  of  the  flower. 

3.  Inside  the  corolla  the  stamens. 


SPERMAPHYTES.  85 

4.  Inside  the  stamens  and  forming  the  middle 
of  the  flower,  the  pistil. 

II.  The  Calyx. 

Five  green-pointed  sepals  attached  around  the 
outer  edge  of  the  receptacle  (expanded  end 
of  flower-stalk). 
Remove  two  sepals.     Sketch. 

III.  The  Corolla. 

Consisting  of  five  brightly  colored  parts, 
petals.  Observe  that  their  insertion  on 
the  receptacle  alternates  with  that  of  the 
sepals. 

Remove  two  or  three  petals.     Sketch. 
IY.  The  Stamens. 

Ten  in  number,  each  consisting  of  a  stalk- 
like  part,  the  filament,  terminated  by  a 
small  expanded  part,  the  anther  The 
filaments  are  united  along  part  of  their 
length.  The  anther  consists  of  two  lobes 
or  thecae,  and  a  very  narrow  connective. 
Sketch  a  stamen. 

Tease  out  an  antlier  in  water  and  examine  with 
D2. 

Numerous  pollen-grains  will  be  found. 
Sketch. 

Y.  The  pistil  is  surrounded  by  a  tube  formed  by 
the  united  filaments  of  the  stamens.  Take 
the  stamens  off  carefully.  The  lower  two 
thirds  of  the  pistil  is  stout  and  green.  The 


86  GENERAL  BIOLOGY. 

upper  third  is  slender  and  five-cleft  at  the 
top  (stigmas).     The  ovary  is  deeply  lobed. 
Sketch. 
Make  a  transverse  section  through  the  ovary. 

How  many  chambers  has  the  ovary?     Where 

are  the  ovules  attached  ?     Sketch. 
VI.  Make  a  diagrammatic  sketch  of  the  flower  in 
longitudinal    section,    showing    the    relative 
position  of  all  its  parts. 
Make  a  diagram  of  the  transverse  section  of  the 

flower. 

In  like  manner  examine,  sketch,  and  make 
diagrams  of  the  violet,  of  a  papilionaceous 
flower,  and  of  a  flower  of  the  lily  or  of  the 
amaryllis  family,  following  in  each  case 
the  order  observed  for  the  geranium,  and 
noting  the  differences. 

For  description  of  irregular  parts,  etc.,  the 
student  is  referred  to  Gray's  "  Manual  of 
Botany,"  under  Violacese,  Leguminosse, 
Liliacese,  Amaryllidacese ;  and  to  Miiller, 
"The  Fertilization  of  Flowers,"  under  Vio- 
lariese,  Leguminosse,  Liliacese,  and  Ama- 
ryllidese. 

GERMINATION  OF  POLLEN-GRAINS. 

Mount  pollen-grains  of  narcissus  or  of  daffo- 
dil in  a  5  per  cent,  solution  of  cane-sugar  in 


8PERMAPHTTE8.  87 

water,  and  of  pansy  or  of  violet  in  a  30  per 
cent,  solution.     Support  the  cover-glass. 
Examine  at  once,  first  with  the  low  and  then 
with  the  high  power.     Look  for  the  nuclei. 
Examine  at  the  end  of  an  hour,  and  again 
after  another  hour. 
Sketch  different  stages. 

SEEDS. 

Examine  seeds  of  the  bean,  of  the  pea,  of 
buckwheat,  of  Indian  corn,  and  of  wheat 
that  have  been  softened  in  water.  Ex- 
amine also  dry  seeds  of  the  castor -oil 
plant. 
I.  Bean. 

1.  Observe  on  one  side  the  oval  spot  (hilum)  to 

which  the  stalk  (funiculus)  that  fastened  the 
seed  to  the  pod  was  attached. 

2.  Find  near  the  hilum  a  minute  opening,  the 

micropyle.  If  the  bean  is  slightly  squeezed 
a  drop  of  liquid  may  be  pressed  out  through 
the  opening. 

Cut  the  seed-coats  along  the  convex  edge  of 
the  bean,  remove  them,  and  examine  their 
inner  surface  for  the  internal  opening  of  the 
micropyle. 

3.  Find   the   chalaza — the   base   of   the  nucellus 

where  the  seed-coats  blend  with  each  other. 


88  GENERAL  BIOLOGY. 

4.  Split  apart  the    cotyledons  and   observe   the 
radicle  and  the  plumule  lying  between  them. 
Sketch. 

What  is  the  position  of  the  radicle  with  refer- 
ence to  the  micropyle  ? 

II.  Pea. 

Examine  in  the  same  way  as  the  bean. 

III.  Castor-oil  Bean. 

Carefully  take  off  the  hard  outer  seed-coat  and 
then  strip  off  the  thin  inner  coat.  Separate 
the  bean  longitudinally  into  two  parts.  Exam- 
ine with  a  hand-lens. 

Find  the  plumule,  the  radicle,  and  the  cotyle- 
dons. Is  there  anything  else  present  ?  What 
differences  are  observable  between  the  castor- 
oil  bean  and  the  common  bean  ? 

IV.  Buckwheat. 

With  a  small  scalpel  take  off  the  outer  seed- 
coat.  Observe  the  thin,  light-colored  coat 
beneath.  Remove  this  carefully,  and  find  the 
parts  enclosed  by  it.  How  do  they  compare 
with  the  parts  within  the  seed-coats  of  the 
bean  and  pea  ?  And  with  Ifhose  of  the  castor- 
oil  bean  ? 

V.  Indian  Corn. 

1.  How   do   the  two  sides   of   the  grain  differ 

in  appearance  ?     Sketch. 

2.  With  a  scalpel  peel  off  the  seed-coats. 
Observe  the  yellow  endosperm.     Kemove  this, 


SPERMAPHYTES.  89 

and  find  the  organ  of  absorption  (scutellum) 
enclosing   the   rest  of  the  embryo  and  in 
close  contact  with  the  endosperm. 
Dissect  out  the  parts  enclosed  by  the  scutellum. 
Observe  : 

(a)  The  radicle  directed  toward  the  small  end 

of  the  grain,  and  the  root-sheath  covering 
its  free  end. 

(b)  The  plumule  at  the  opposite  end  of  the 

embryo.     Its  outer  leaf  is  the   cotyle- 
don. 

(c)  The  caulicle,  the  attachment  between  the 

scutellum  and  the  rest  of  the  embryo. 
3.    With  a  razor  make  a  median  longitudinal  section 
through  the  broad  sides  of  a  grain.     Observe 
on  the  cut  surface  : 

(a)  The  tough  outer  membrane,  composed  of 

the  united  coats  of  the  fruit  and  the 
seed. 

(b)  The  endosperm,  consisting  of  starch  and 

other  food-materials. 

(c)  The  embryo,  with  its  organ  of  absorption, 

the  scutellum. 

Sketch  the  section  much  enlarged. 
YL  Wheat, 

Examine  the   seed  entire,  and  then  find  the 

parts  of  which  it  consists. 
Sketch. 


90  GENERAL  BIOLOGY. 

SEED-CONTENTS. 

I.  Pea. 

Cut  thin  sections  of  the  cotyledons.  Mount 
some  in  dilute  glycerine  and  others  in 
water. 

1.  In  the  glycerine  preparations  observe  in  each 

cell: 

(a)  Large  starch-grains. 

(b)  Small  aleurone-grains. 

(c)  Very  finely  granulated  substance. 
Observe  the  intercellular  spaces. 

Sketch  one  or  two  cells  with  cell-contents. 

2.  Compare  the  glycerine-preparation  with  the 

water  preparation. 

Add    iodine    to   the    glycerine   preparation. 
What  is  the  effect  ? 

II.  Bean. 

Examine  as  Pea. 

III.  Wheat. 

Cut  thin  sections  at  right  angles  to  the  seed- coat  y 
and  mount  them  in  dilute  glycerine. 
Observe : 

(a)  Just  within  the  seed-coat  a  layer  of  rec- 

tangular    cells     containing     aleuTone- 
grains. 

(b)  More  centrally  situated,  cells  containing 

starch.      Add    iodine.      What    is    the 
effect  ? 
Sketch  a  few  cells. 


SPERMAPH7TES.  91 

IV.  Castor-oil  Bean. 

Gently  remove  the  brittle  seed- coat,  separate  the 
cotyledons,  and  make  very  thin  sections  of 
the  endosperm. 

Mount  some  in  pure  glycerine  and  some  in 
water.  Put  others  into  a  drop  of  alcoholic 
solution  of  eosin  on  a  slide.  After  Jive 
minutes  remove  the  eosin  with  filter-paper, 
add  50  per  cent,  alcohol  and  a  drop  of 
glycerine,  and  put  on  a  cover-glass. 

1.  Study  first   the  glycerine    preparation.     Ob- 

serve :     large     aleurone-grains     containing 
spherical  bodies  (globoids). 

2.  Compare    the    water    preparation   with    the 

glycerine  preparation.     What  difference  is 
observable  ? 

Add   iodine   to    the    glycerine    preparation. 
What  is  the  effect  ? 

3.  In  the  stained  preparation  look  for  crystalloids 

in  the  aleurone-grains. 
Sketch. 

SEEDLINGS. 
I.  Dicotyledons. 
A.  Observe  in  the  earlier  stages  the  way  in  which 

the  seedling  breaks  through  the  ground. 
Examine  and  sketch  different  stages  of  each  of  the 
following  forms : 

1.  Pea. 

2.  Bean. 


92  GENERAL  BIOLOGY. 

3.  Buckwheat. 

4.  Mustard. 

B.  Comparison  of  different  kinds  of  seedlings. 

(After  examining  and  sketching  the  second  com- 
pare it  with  the  first.  In  like  manner  compare 
the  third  with  the  first  and  second,  and  the 
fourth  with  the  first,  second,  and  third.) 

1.  Compare  the  roots. 

2.  Has  each  a  stem  supporting  the  cotyledons 

(hypocotyl)  ? 

3.  Compare  the  cotyledons  : 

(a)  In  regard  to  form  and  size. 

(b)  What    might   be   inferred   as    to   their 

function  ? 

4.  Compare  the  cotyledons  of   the   pea  and  of 

the  bean. 

5.  Compare  the  pea  and  the  buckwheat  as  to  the 

time  of  appearance  of  the  foliage  leaves. 
To  what  may  the  difference  be  due  ? 
II.  Monocotyledons. 

Observe  and  compare  different  stages  of  the 
following  forms : 

1.  Indian  corn. 

2.  Wheat. 

HI.  Compare  the  seedlings  studied  in  I.  with  those 
in  II. 

1.  Observe  the  number  of  cotyledons. 

2.  Compare  their  form  with  that  of  the  foliage 

leaves. 


SPERMAPHYTES.  93 

3.  Note  the  venation  of  the  foliage  leaves  and 

their  arrangement  on  the  stem. 

4.  What  is  the  character  of  the  root-system  ? 

ROTATION  AND  CIECULATION  or  PEOTOPLASM. 

I.  Mount  in  water  a  duster  of  young  leaves  of  Nitella. 

Examine  with  AA  2  and  D  2. 
Observe : 

1.  The  chlorophyll-grains  arranged  in  rows. 

2.  The  neutral  zone,  free  from  chlorophyll. 

3.  The  current  of   protoplasm   just   below  the 

level  of  the  chlorophyll-grains. 
Diagram  ! 

II.  Mount  in  water  one  or  more  hairs  from  the  filament 

of  the  stamen  of  Tradescantia. 

With  AA  2  note  the  rosary-like  appearance  of 
the  hair.  Study  with  the  high  power  and  see 
the  active  circulation  of  currents  of  protoplasm 
around  and  through  the  central  vacuole, 

Diagram  ! 

STAECH  WITHIN  CHLOEOPHYLL-GEAINS. 
I.  Mount  in  water  some  pieces  of  Nitella  leaves. 

Note  especially  at  the  cut  ends  the  chlorophyll- 
granules  containing  highly  refractive  bodies — 
starch-grains. 

1.  Draw  some  iodine  solution  under  the  cover- 

glass.     What  parts  are  stained  ? 
Diagram  ! 

2.  Mount  another  specimen  of  Nitella  and  add 


94  GENERAL  BIOLOGY. 

chloral-hydrate  iodine.     Watch  a  few  min- 
utes for  the  effect. 

KAEYOKINESIS. 

1.  The  tip  of  a  young  onion-root.* 

Find  and  sketch  seven  or  eight  stages. 

2.  The  testis  of  the  lobster.f 
Find  the  principal  stages. 

Sketch. 

*  Method  of  preparation  :  Cut  off  a  quarter  of  an  inch  of  the  tip 
of  young  roots  of  an  onion  growing  in  water  in  a  hyacinth- 
glass  ;  put  them  into  Hermann's  fluid  in  the  dark  for  48  hours  ; 
wash  in  running  water  24  hours ;  imbed  in  paraffine  and  stain  on 
the  slide  with  Haidenhain's  iron-hsematoxylin,  leaving  the  sec- 
tions in  the  haematoxylin  solution  overnight. 

f  Pieces  of  the  testis  a  quarter  of  an  inch  long  should  be  pre- 
served and  stained  as  the  onion-root.  In  making  the  sections  the 
pieces  of  testis  should  be  cut  lengthwise. 


FROG. 

For  an  economical  use  of  material  this  order  may 
be  observed  : 

For  the  first  day's  work  follow  sections  I-III  in- 
clusive, and  in  YI  the  directions  for  exposing  and 
hardening  the  central  nervous  system.  This  frog 
should  then  be  put  into  formic  aldehyde  solution  of 
1  to  2  per  cent.,  which  is  especially  good  for  hard- 
ening the  nervous  system.  If  the  odor  of  the  formic 
aldehyde  is  unpleasant,  the  material  may  be  rinsed 
in  dilute  ammonia  before  being  used. 

Taking  a  fresh  frog  on  the  second  day,  work  out 
upon  it  the  circulatory  and  urino-genital  systems, 
sections  IY  and  Y.  This  frog  should  be  kept  in 
Wickersheimer's  fluid,  which  preserves  it  in  good 
condition  for  the  study  of  muscles,  etc. 

After  a  few  days  the  brain,  etc.,  of  the  first  frog 
will  have  become  sufficiently  hardened,  and  the 
work  may  proceed  in  regular  sequence.  The  direc- 
tions after  YI  may  be  worked  out  upon  either  frog, 
as  the  material  serves. 

For  this  work  on  the  frog  it  is  sufficient  to  use  a 
water  solution  containing  from  1  to  2  per  cent,  of 
formic  aldehyde.  "Formalin"  is  properly  a  com- 
mercial name  for  a  40  per  cent,  solution  of  formic 

95 


96  GENERAL  BIOLOGY. 

aldehyde  in  water,  but   is   often   used  indiscrimi- 
nately for  solutions  of  various  strengths. 

I.  External  Characters. 

1.  The  division  of  the  frog  into  head,  trunk,  and 

limbs. 

2.  The    skin:    moist    and    smooth.      Note    its 

looseness. 

Make  short  slits  in  several  places  and  inflate  the 
lymph-sacs. 

3.  The  head  :  its  shape. 

(a)  The   eyes :    each  with  two   eyelids   (are 

they  movable  ?). 

(b)  The  tympanic  membranes;  modified  parts  of 

the  skin  covering  the  ears. 

(c)  The  nostrils  or  anterior  nares. 

4.  The  limbs. 

(a)  The  anterior   limb  is  divided  into  three 

regions :  brachium,  antibrachium,  and 
maims.  The  manus  has  four  digits.  In 
the  breeding  season  the  first  digit  of  the 
male  bears  a  swollen  cushion. 

(b)  The  posterior  limb  is  divided  into  three 

regions  :  femur,  cms,  and  pes.  The  pes 
has  five  digits  connected  by  a  web. 

5.  Identify  all  openings  into  the  body. 

6.  Look  at  a  living  frog  in  an  aquarium-jar  with 

a  little  water  to  see  its  position,  its  eyes, 
etc.,  and  its  mode  of  breathing. 


FROG.  97 

Make  an  outline  sketch  of  the  dorsal  aspect  of  the 
frog, 

II.  The  Buccal  Cavity. 

Open  the  mouth  and  note  : 

1.  Its    wide    cavity ;    the    posterior    part,    the 

pharynx,  is  continuous  with  the  oesoph- 
agus. 

2.  The  teeth  : 

(a)  On  the  upper  jaw. 

(b)  On  the  roof  of  the  mouth. 

3.  The  posterior  nares. 

To  find  them,  pass  bristles  into  the  anterior 
nares  and  note  the  points  of  entrance  into 
the  mouth-cavity. 

4.  The  Eustachian  recesses :  a  pair  of  lateral  pro- 

longations of  the  mouth-cavity.  Pass  a 
bristle  through  the  tympanum  from  the 
outside  and  note  the  place  of  its  entrance 
into  the  mouth- cavity. 

5.  The  tongue.     Note  its  shape  and  its  attach- 

ment.    Turn  it  forward  to  see  : 

6.  The  glottis  :  a  longitudinal  slit  in  the  floor  of 

the  mouth. 
Pass  a  probe  into  it. 

III.  The  Abdominal  Viscera. 

Lay  the  frog  iipon  its  hack  in  a  pan  containing 
wax,  and  fasten  it  down  with  pins  through  the 
limbs.  Cut  through  the  skin  along  the  median 
ventral  line,  and  make  a  transverse  cut  at 


98  GENERAL  BIOLOGY. 

each  end  of  the  first.      Turn  the  flaps  of  skin 
outward  and  pin  them  down. 
Observe  : 

1.  On  the  skin  near  the  shoulder  the  musculo- 

cutaneous  vein. 

2.  The  body-wall,  formed  of  muscles. 

3.  In  the  median  ventral   line  the  anterior  ab- 

dominal vein. 

Put  a  double  ligature  on  this  by  making  a  slit 
on  each  side  of  the  vein  and  tying  two  threads 
around  it  near  together.  Raise  the  body -ic  all 
with  forceps,  and  with  scissors  carefully  con- 
tinue the  cut  on  the  left  side  of  the  vein  from 
pelvis  to  sternum.  Make  a  transverse  cut 
between  the  ligatures  and  extending  across  the 
ventral  aspect  of  the  body. 
Note  the  anterior  abdominal  vein  passing 
dorsally  into  the  liver. 

With  scissors  cut  in  the  median  line  through  the 
sternum  and  other  superficial  parts,  taking 
care  not  to  injure  the  parts  beneath.  Turn 
each  half  outward  and  pin  firmly . 

4.  Sketch  the  organs  exposed  to  view  and  identify 

them.     {Remove  the  ovaries  if  they  conceal 
the  other  organs.) 

(a)  The  heart. 

(b)  The  liver  :  reddish  brown  and  bilobed. 

(c)  The  lungs. 


FROG.  99 

(d)  The  stomacli :    lying  partly  beneath  the 

left  lobe  of  the  liver. 

(e)  The    small     intestine :     a     light-colored 

slightly  convoluted  tube.  It  passes 
posteriorly  into  the  large  intestine. 
The  terminal  part  of  the  large  intestine 
is  the  cloaca.  Note  the  mesentery  by 
which  the  intestine  is  attached  to  the 
dorsal  body-wall. 

(/)  The  bladder :  a  thin-walled  bilobed  sac 
in   the    posterior  ventral   part   of    the 
body-cavity. 
Insert  a  bloivpipe  into  the  glottis  and  inflate. 

The  lungs,  if  hidden  before,  will  now  come 

into  view. 

Pass    a  probe  into   the  mouth    and   through   the 

oesophagus   into   the  stomach.      Turn   the    liver 

forward    to    see    the    oesophagus   and   stomach. 

Uncoil    the    intestine    and    identify    its    parts. 

Find  : 

(g)  The  pancreas,  in  the  loop  between  the 

stomach  and  duodenum. 
(h)  The   spleen,    in  the   mesentery  near  the 

beginning  of  the  large  intestine. 
(i)  The  two  lobes  of  the  liver.  Observe  that 
the  larger  lobe  is  subdivided  into  two. 
Note  the  position  of  the  gall-bladder. 
Make  a  slight  slit  in  the  duodenum  and 
try  by  pressing  upon  the  gall-bladder 


100  GENERAL  BIOLOGY. 

to  make  the  bile  pass  to  the  duodenum. 
Look  now  for  the  bile-duct. 
(/)  The  fat  bodies  :  long  slender  yellow  masses 
on   each   side,   attached   to  the  dorsal 
wall   of   the  body-cavity  at  about   the 
level  of  the  posterior  border  of  the  liver. 
In  different  specimens  they  vary  much 
in  size. 
Identify  : 

(k)  The  reproductive  organs. 
IY.  The  Circulatory  Organs. 

Open  the  per  icar  dial  cavity,  using  great  care  not 
to  injure  the  anterior  abdominal  vein  which 
passes  dorsally  in  the  posterior  wall  of  the 
pericardium. 

1.  Examine  and  sketch  the  heart,  showing  its 
parts : 

(a)  The  auricles  :  dark  colored  and  with  thin 

walls. 

(b)  The  ventricle  :  of  paler  color  and  conical. 

(c)  The  truncus  arteriosus:   arising   from    the 

anterior  side  of  the  ventricle,  passing 
obliquely  forward  and  dividing  into  two 
large  branches. 

Turn  the  apex  of  the  heart  forward  and  note 
on  its  dorsal  side  : 

(d)  A  darker   triangular-shaped   region,  the 

sinus  venosus.  It  is  closely  related  to  the 
auricles,  and  receives  the  great  veins. 


FROG.  101 

2.  Observe  the  contractions  of  the  heart.     Note 

the  order  of  sequence  of  the  contraction 
in  the  four  parts  of  the  heart.  The  heart  of 
lower  vertebrates  often  continues  to  beat 
after  the  death  of  the  animal. 

3.  The  veins. 

A.  The  Anterior  Abdominal  Vein  and  its  Trib- 

utaries. 

(a)  Trace  the  course  of  the  anterior  abdominal 

vein  into  the  liver.  Just  before  its  en- 
trance it  divides  into  two  branches,  one 
going  to  each  main  lobe  of  the  liver. 

(b)  Trace  it  posteriorly.     It  is  formed  by  the 

union  of  two  pelvic  veins  which  are 
ventral  branches  of  the  femoral  veins. 

(c)  Trace  the  pelvic  vein  of  one  side  back  to 

the  femoral  from  which  it  arises. 

(d)  Follow   the  femoral  vein  posteriorly,  to 

see  from  what  region  it  is  bringing 
blood. 

B.  The  Kenal  Portal  System. 

(a)  The  dorsal  branch  of  the  femoral  vein  is 
the  renal  portal  vein.  It  receives  the 
sciatic  vein  and  small  veins  from  the 
body-wall,  etc.  The  renal  portal  vein 
passes  forward  to  the  outer  side  of  the 
kidney  and  enters  that  organ  by  means 
of  numerous  branches. 

C.  The  Hepatic  Portal  System. 


102  GENERAL  BIOLOGY. 

(a)  Raise    the   liver   and  find    the  vein   that 
enters   its    left   lobe,  the   hepatic  portal 
vein.     Trace  it  posteriorly  and  find  the 
veins  that  unite  to  form  it : 
(act)  The  gastric  vein  :  from  the  stomach. 
(bb)    The  intestinal  veins. 
(cc)    The  splenic  vein. 

The  hepatic  portal  vein  just  before  entering  the 
liver  gives  off  a  branch  that  anastomoses  with 
the  anterior  abdominal  vein. 
D.  Yeins  Opening  into  the  Sinus  Venosus. 

(a)  The    inferior  vena  cava:    a    median    vein 

which  opens  into  the  posterior  part  of 
the  sinus  venosus.  It  brings  blood  to 
the  heart  from  the  liver  and  kidneys, 
etc.,  and  from  the  hind  limbs.  It  is 
made  up  by : 

(aa)  The  renal  veins  :  from  the  kidneys. 
(bb)  The  genital  veins, 
(cc)    The  right  and  left  hepatic  veins  from 
the    liver.      These    open    into  the 
vena  cava  inferior  close  to  the  sinus 
venosus. 

(b)  The    right   superior  vena  cava.     It  brings 

back  blood  from  the  right  side  of   the 
head  and  body  and  from  the  right  fore- 
limb.     It  is  formed  by  : 
(aa)  The  external  jugular  vein  :  formed  by: 


FROG.  103 

(aaa)  The    lingual    vein :     from    the 

tongue. 
(bbb)    The  inferior  maxillary  vein  :  from 

the  lower  jaw. 
(bb)  The  innominate  vein  :  formed  by 

(aaa)  The  internal  jugular  vein  :    from 

the  brain,  etc. 
(bbb)   The  subscapular  vein :  from  the 

muscles  of  the  shoulder. 
(cc)  The  subclavian  vein  :  formed  by 

(aaa)  The  brachial  vein :  from  the  fore- 
limb. 
(bbb)   The    musculo  -  cutaneous    vein 

from  the  skin,  etc. 

(c)  The  left  superior  cava :  similar  to  the  right. 
E.  Yein  Opening  into  the  Left  Auricle, 
(a)  The  pulmonary  vein  :  formed  by"  the  union 
of  the  right  and  left  pulmonary  veins. 
Each   pulmonary  vein  runs    along   the 
inner  side  of  its  lung. 
Diagram  of  the  veins  ! 
4.  The  Arteries. 

Distend  the  oesophagus  by  inserting  the  rubber 
top  of  a  pipette  or  a  roll  of  paper,  and  thus 
stretch  the  arteries. 

Note  the  division  of  the  truncus  arteriosus 
into  two  branches,  and  that  each  of  these 
is  subdivided  into  three  aortic  arches : 


104:  GENERAL  BIOLOGY. 

(a)  The  anterior  or  carotid  arch.      Its  chief 

branches  are  : 

(aa)  The  lingual  artery  :  to  the  tongue. 
(bb)  The  carotid  artery :  to  the  brain,  etc. 

(b)  The  middle  or  aortic  arch.     It  runs  around 

the  throat  to  the  vertebral  column  and 
unites  with  its  fellow  to  form  the  dorsal 
aorta.     It  gives  off  on  each  side  at  the 
level  of  the  arm  : 
(aa)  The  subclavian  artery :    to   shoulder 

and  fore-limb. 

(bb)  The  vertebral  artery :  to  the  vertebral 
column  and  back,  etc. 

(c)  The  third,  posterior,  or   pulmonary  arch: 

to  the  lung  on  each  side.  On  the  way 
it  gives  off: 

(aa)  The  cutaneous  artery :    to  the    skin, 
etc. 

(d)  The  dorsal  aorta  and  its  branches. 
Posterior  to  the  union  of  the  two  aortic 

arches  the  dorsal  aorta  lies  in  the 
median  line  just  ventral  to  the  vertebral 
column.  It  gives  off  the  following 
branches : 

(aa)  The  coeliaco-mesenteric  artery :  a  me- 
dian artery  to   the   stomach   and 
intestine.     Its  branches  are  : 
(aaa)  The     ereliac     artery:     to    the 
stomach  and  to  the  liver. 


FROG.  105 

(bbb)  The   mesenteric  artery :   to  the 

intestine  and  to  the  spleen. 
(bb)  The  renal  arteries :  to  the  kidneys. 
(cc    The  genital  arteries  :  to  the  reproduc- 
tive organs. 

(dd)  The  inferior  mesenteric  artery:  sup- 
plying the  base  of  the  large  intes- 
tine. 

(ee)  The  common  iliac  arteries  :  formed  by 
the  division  of  the  dorsal  aorta. 
Each  continues  down  the  leg  as 
the  sciatic  artery  after  having 
given  off: 
(aad)  The  hypogastric  artery :  to  the 

bladder. 

Diagram  of  the  Arterial  System  ! 
T.  The  Urino-genital  Organs. 

Remove  the  alimentary  canal  between  the  base  of 
the   oesophagus   and   the  posterior  third  of  the 
large  intestine. 
Posterior  to  the  fat  bodies  are  the  reproductive 

organs. 
In  the  female  : 

1.  The  ovaries  :  lobed  organs,  varying  much  in 

size  with  the  season  of  the  year. 

2.  The  oviducts  :  convoluted  tubes,  one  on  each 

side.  The  anterior  end  is  funnel-like,  and 
the  tub.e  passes  posteriorly  to  open  into  the 
cloaca. 


106  GENERAL  B10LOOJ. 

3.  The  kidneys  :  elongated  red  masses  close  to 

the  vertebral  column. 

4.  The  adrenal  bodies :  a  band  of  yellow  tissue  on 

the  ventral  side  of  each  kidney. 

5.  The  ureters  :  two  whitish  tubes  passing  from 

the  outer  edge  of  the  kidney  to  the  cloaca 
In  the  male  : 

1.  The    testes :    a   pair    of  yellowish   rounded 

bodies. 

2.  The   genital    ducts    (vasa  efferentia)   placing 

each  testis  in  communication  with  the 
kidney  of  the  same  side.  In  the  male  the 
ureter  serves  also  as  a  genital  duct. 

3.  The  kidneys,  as  in  the  female  (see  above). 

4.  The  adrenal  bodies,  as   in  the  female  (see 

above). 

5.  The  ureters,  as  in  the  female  (see  above). 
Diagram  of  the  Reproductive  Organs  ! 

VI.  The  Nervous  System. 

A.  The  Central  Nervous  System. 
Cut  the  skin  along  the  median  dorsal  line  and 
turn  it  back.  Remove  the  muscles  from  the 
vertebrae.  Open  the  neural  canal  by  cutting 
the  membrane  between  the  skull  and  the  first 
vertebra.  Remove  the  roof  of  the  brain-cavity 
gradually,  bit  by  bit,  with  small  strong  for- 
ceps or  with  small  strong  scissors.  In  the 
same  way  remove  the  neural  arches  of  the 
vertebrce. 


FROG.  107 

Note  the  delicate  pigmented  membranes  that 
cover  the  brain  and  the  spinal  cord.  The 
outer,  the  dura  mater,  is  often  more  or  less 
torn  in  removing  the  bone.  The  inner,  the 
pia  mater,  lies  very  close  upon  the  nervous 
tissue.  It  is  usually  more  pigmented  than 
the  dura  mater. 

Before  the  brain  can  be  removed  for  further 
investigation  it  must  be  hardened  by  ex- 
posure to  formic  aldehyde. 
To  remove  the  brain  : 

Cut  through  the  olfactory  tracts  (or  nerves)  close 
to  the  nasal  pits  •  lift  the  anterior  end  of  the 
brain  gently ,  cut  through  the  cranial  nerves 
close  to  the  skull  and  through  the  spinal 
nerves.  Take  out  the  brain  and  spinal  cord 
and  put  into  a  small  dish  of  water  (or  dilute 
alcohol). 

Sketch  the  nervous  system  thus  exposed : 
1.  The  brain  :   the  dorsal  aspect  (from  before 
backward) : 

(a)  The  olfactory  lobes,  each  passing  anteriorly 

into  a  cylindrical  portion  :  the  olfactory 
tract. 

(b)  The  cerebral  hemispheres,  separated  from 

each  other  by  a  deep  cleft.  They  are 
marked  off  from  the  olfactory  lobes  by 
a  slight  transverse  depression. 

(c)  The  thalamencephalon:  immediately  behind 


108  GENERAL  BIOLOGY. 

the  cerebral  hemispheres.  In  the  middle 
line  between  the  diverging  ends  of  the 
cerebral  hemispheres  the  pineal  gland 
is  borne. 

(d)  The  optic  lobes:  two  conspicuous  rounded 

bodies,  one  on  each  side. 

(e)  The  cerebellum:  a  narrow  ridge  posterior 

to  the  optic  lobes. 

(/)  The  medulla  oblongata:  the  region  posterior 
to  the  cerebellum,  broadest  at  the  an- 
terior end  and  passing  gradually  into 
the  spinal  cord.  Its  dorsal  wall  is  a 
thin,  highly  vascular  membrane,  the 
choroid  plexus  of  the  fourth  ventricle. 
Beneath  the  choroid  plexus  is  the  cav- 
ity of  the  fourth  ventricle. 

2.  The  Spinal  Cord  :  continued  posteriorly  from 

the  medulla  oblongata.  It  is  flattened 
dorso-ventrally.  Near  the  region  of  the 
sixth  vertebra  it  tapers  rapidly  to  a  slender 
thread,  the  filum  terminale.  The  filurn  ter- 
minale  and  the  proximal  ends  of  the  lumbar 
nerves  form  the  cauda  equina.  Note  in  the 
median  line  a  slight  groove  not  well  marked 
throughout,  the  dorsal  fissure. 
Turn  the  brain  and  spinal  cord  ventral  side  upper- 
most, and  sketch.  Note : 

3.  The  Brain  : 

(a)  The  olfactory  lobes  and  nerves. 


FROG.  109 

(b)  The  cerebral  hemispheres. 

(c)  The  optic  chiasma :  ventral  to  the  posterior 

end  of  the  hemispheres.  Trace  the 
bundles  of  fibres  as  far  as  possible. 

(d)  The  tuber  cinereum :  a  shield-shaped  body 

posterior  to  the  optic  chiasma.  On  its 
posterior  border  attached  by  a  slender 
stalk  : 

(e)  The  pituitary  body. 

(/*)  On  each  side  of  the  pituitary  body  the 
crura  cerebri :  two  columns  of  fibres  con- 
necting  the  cord  and  the  medulla  with 
the  anterior  part  of  the  brain. 

4.  The  Spinal  Cord,  continued  posteriorly  from 

the   medulla.     Note   the   median  (ventral) 
fissure  throughout  its  length. 

5.  The  Cavities  of  the  Brain. 

With  a  razor  make  a  horizontal  cut  midway 
between  the  dorsal  and  the  ventral  sides  to 
show : 

(a)  In  the  cerebral  hemisphere  on  each  side 

the  lateral  ventricle. 

(b)  Connecting  the  two  lateral  ventricles  the 

foramen  of  Monro. 

(c)  In  the   optic   lobes  the   ventricles  of  the 

optic  lobes. 

(d)  Connecting  (a)  and  (c)  the  third  ventricle. 

(e)  In  the  medulla  the  fourth  ventricle. 
B.  The  Sympathetic  Nervous  System. 


110  GENERAL  BIOLOGY. 

Lay  the  frog  ventral  side  up  and  carefully  re- 
move ike  digestive,  excretory,  and  reproductive 
organs. 
Observe  : 
1.  Along  the  vertebral  column  on  each  side  and 

close  to  the  dorsal  aorta  a  slender  cord. 
With  great  care  raise  it  slightly  and  note  : 
The  yellowish  enlargements  along  its  length, 

the  sympathetic  ganglia. 
Count  the  ganglia,  being  careful  not  to  injure 

them. 

C.  The  Peripheral  Nervous  System. 
1.  Spinal  Nerves :  passing  out  from  between  the 

vertebrae.     Count  those  of  one  side. 
Gently  raise  the  sympathetic  cord,  and  note 
the  branch  from  each  spinal  nerve  to  a 
sympathetic  ganglion. 

Note  the  grouping  of  the  spinal  nerves  into 
plexuses  : 

(a)  The  sciatic  plexus;  formed  from  the  7th, 

8th,  and  9th  spinal  nerves.  From  the 
plexus  the  sciatic  nerve  is  given  off. 
Trace  this  into  the  leg. 

(b)  The  brachial  plexus  :  formed  from  the  2d 

and  3d  spinal  nerves.  It  gives  rise  to 
the  brachial  nerve.  Trace  this  nerve 
into  the  arm. 

Between  these  two  plexuses  the  4th,  5th,  and 
6th  spinal  nerves  pass   out  separately  as 


FROG.  Ill 

small  nerves  to  the  muscles  and  skin  of 
the  body -wall. 

Diagram  of  the  sympathetic  ganglia  and  their 
principal  nerves,  and  of  the  spinal  nerves 
of  one  side. 

VII.  The  Eye. 

With  fine  scissors  make  an  incision  in  the  skin 
above  the  eyeball.  Continue  this  cut  around 
the  edge  of  the  socket.  Lifting  the  eyeball 
by  the  edge  of  the  skin,  cut  it  free  from  the 
muscles  and  nerve  beneath.  Take  out  both 
eyes  and  harden  them  for  two  or  three  days 
in  formic  aldehyde  solution. 
Divide  one  eye  into  right  and  left  halves, 

and  one  into  proximal  and  distal  halves. 
Observe : 

1.  The  sclera.  4.  The  retina. 

2.  The  cornea.  5.,  The  lens. 

3.  The  choroid  coat.     6.  The  vitreous  humor. 

VIII.  Muscles. 

Cut  through  the  skin  around  the  junction  of 
the  leg  with  the  body,  and  strip  the  skin 
from  the  leg. 

Bend  the  leg,  and  try  to  distinguish  the 
flexors  and  extensors.  Dissect  the  leg 
to  show  the  sartorius  and  gastrocnemius 
muscles.  (See  diagram.)* 

*  Enlarged  from  Figs.  80  and  81,  Ecker's  "Anatomy  of  the 
Frog,"  translated  by  G.  Haslam.     Clarendon  Press,  1889. 


112  GENERAL  BIOLOGY. 

How  does  a  muscle  begin  and  how  does  it 

end?     Compare  the  middle  with  the  end. 
IX.  Bones. 

Examine  the  articulation  of  the  femur  with 

the  pelvis.     Observe  the  end  of  the  bone, 

cartilage,  etc. 
Clean  up  the  knee-joint,  the  pelvis,  one  or 

two  vertebrae,  and  the  skull,  and  see  their 

parts. 


FISH. 

I.  External  Characters. 

1.  Make   an   outline  sketch    showing   the   fins, 

orifices,  etc. 

2.  Find  the  operculum.     Lift  it  up  and  find  : 

3.  The  gills.    How  many  are  there?    How  many 

slits  between  the  gills  (gill-clefts)  ? 

II.  Abdominal  Viscera. 

Cut  through  the  body-ivall  on  loth  sides  along  the 
lines  indicated  in  the  diagram.*     Remove   the 
portion  of  body -wall  thus  cut  out. 
Observe  : 

1.  The  liver,  a  conspicuous  brownish  lobed  organ. 

Lift  it  up  to  see  : 

2.  The  gall-bladder. 

3.  The  hepatic  veins,  passing   anteriorly  from 

the  liver. 

4.  The  stomach,  partly  concealed  by  the  liver. 

5.  The  intestine,  passing  posteriorly  from  the 

stomach  with  one  or  two  turns  to  the  anus. 

*  An  outline-diagram  of  the  fish  with  lines  to  mark  places  for 
cutting : 

1.  Antero-posteriorly :  parallel  and  slightly  ventral  to  the  lateral 

line. 

2.  Dorso-ventrally  from  the  median  ventral  line  to  meet  the 

first  cut: 

(a)  An  inch  in  front  of  the  anus. 

(6)   Obliquely  just  posterior  to  the  pectoral  and  pelvic 
girdles. 

113 


114  GENERAL  BIOLOGY. 

6.  The  pyloric   appendages,    finger-like    organs 

opening  into  the    alimentary  canal  at  the 
junction  of  stomach  and  intestine. 

7.  The  spleen,  a  dark  red  body  lying  in  one  of 

the  loops  of  the  intestine. 

8.  The  reproductive  organs. 

9.  The  air-bladder. 
Diagram  ! 

Cut  through  the  intestine  an  inch  from  the  anus 
and  through  the  hepatic  veins  close  to  the  liver, 
and  remove  all  the  organs  thus  far  seen  except 
the  air-bladder. 

Cut  through  the  air-bladder  (noting  the  rete 
mirabile  on  its  ventral  ivall)  to  see : 

10.  The  kidneys,  elongated  red  organs  pressed 

close  to  the  dorsal  wall  of  the  abdominal 
cavity,  one  on  each  side  of  the  vertebral 
column.  Put  a  bristle  into  the  outer  open- 
ing of  the  ureter  and  trace  it  to  the  kid- 
neys. 
Find: 

11.  The  genital  duct. 

Diagram  of  the  kidneys  and  reproductive  organs. 
III.  Circulatory  System. 

Dissect  away  the  left  half  of  the  pelvic  and  pec- 
toral girdles  from  below  upward,  not  injuring 
the  veins. 
Observe : 


FISH.  115 

1.  The  pericardial  cavity  and  the  septum  sep- 

arating it  from  the  abdominal  cavity. 

2.  The  heart . 

(a)  The  sinus. 

(b)  The  auricle. 

(c)  The  ventricle. 

(d)  The  bulbus  (conus). 
Diagram 

3.  Find  the  veins  coming  to  the  heart : 

(a)  The  hepatic  veins,  passing  through  the 
septum  from  the  abdominal  cavity  and 
opening  into  the  sinus. 

(6)  The  pre-caval  veins  (ducts  of  Cuvier),  one 
on  each  side  formed  by  the  union  of 
the  jugular  vein  from  the  anterior  and 
of  the  cardinal  vein  from  the  posterior 
region,  passing  ventrally  along  the  sep- 
tum and  opening  into  the  sinus. 

4.  Trace  the  ventral  aorta  from  the  bulbus  and 

find  its  branches. 

5.  Find  the  dorsal  aorta  (dorsal  to  the  air-blad- 

der) and  trace  it  forward  into  the  ceph- 
alic circle. 

Diagram  of  the  veins  and  arteries. 
IV.  Exoskeleton. 

Take  off  several  scales  from  different  parts 
of   the    body.        Examine   with   a   low 
power. 
Sketch. 


PIGEON. 

I.  External  Characters. 

1.  Note  the  shape  of  the  head,  the    neck,  the 

trunk,  and  the  tail. 

2.  Note  the  arrangement  of  feathers  in  the  body, 

the  wing,  and  the  tail.  Pull  out  some  of 
each  of  the  different  kinds  and  keep  them 
for  examination. 

3.  Sketch  the  head.  How  many  openings  ?  Com- 

pare with  those  of  the  frog. 

4.  Observe  the  different  parts  of  the  wing  and 

of  the  leg.  Find  the  hand  and  the  foot. 
Note  the  attachment  of  the  feathers.  "What 
forms  the  covering  of  the  foot  ? 

5.  Pluck. 

(This  can  be  done  more  easily  if  the  skin  of  the 
bird  is  first  thoroughly  wet  with  very  hot 
water.  Great  care  should  be  taken  when 
pulling  out  feathers  from  the  neck  not  to 
tear  the  skin  of  that  region.) 

II.  The  Abdominal  Yiscera. 

Make  a  median  longitudinal  cut  through  the 
skin  on  the  ventral  surface  of  the  body  and 
neck,  being  careful  not  to  cut  deeper. 

Turn  back  the  skin,  and  keeping  it  moist,  note  : 

1.  The  oesophagus  and  crop. 

2.  The  trachea. 

116 


PIGEON.  117    - 

3.  The  blood-vessels  (be  careful  not  to  injure 

them). 

Slit  the  trachea  transversely  in  the  middle  neck- 
region  and  ligature  the  neck  through  the  slit 
and  under  (i.e.,  not  including)  the  skin.  Cut 
.off  the  head  above  the  ligature.  Open  the 
brain-cavity  by  shaving  off  the  bone,  exposing 
cerebrum  and  cerebellum,  and  put  the  head  at 
once  into  formic  aldehyde  solution  (as  for 
frog's  brain). 

JtfaJce  a  transverse  cut  through  the  body-wall 
of  the  abdomen  posterior  to  the  pectoral 
muscles. 

4.  Note  the  air-sacs.     How  many  are  visible  ? 

5.  Observe  the  intestine  and  the  fat  in  the  mes- 

entery. 

6.  Find  the  falciform  ligament,  a  thin  membrane 

with  a  large  vein,  in  the  median  vertical 

plane  and  attached  to  the  middle  line  of 

the  sternum  beneath  the  keel. 
7.  Insert  a  tube  into  the  trachea  and  bloiv  up  the 

structures  connected  with  it.     (Compare  II. 

4.,  above.) 

Holding  the  sternum  with  the  right  hand  press 
gently  with  the  left  thumb  upon  the  part  of 
the  crop  that  lies  against  the  pectoral  muscles 
and  thus  separate  the  crop  from  the  anterior 
border  of  the  sternum. 
Note  beneath  the  crop  : 


118  GENERAL  BIOLOGY. 

8.  A  bilobed   sac  in  the  angle  formed  by  the 

furcula,  the  interclavicular  air-sac. 

9.  Dorsal   to  each  lobe  of    the  interclavicular 

air-sac  is  one  of  the  paired  prebronchial  air- 
sacs. 

Cut  through  the  left  pectoralis  major  muscle  dose  to 
the  keel  of  the  sternum  along  its  whole  lengthy  half 
an  inch  deep  at  the  anterior  end  and  less  deep  as 
the  posterior  end  is  approached.  From  the 
anterior  end  continue  the  cut  laterally  and 
dorsally  to  separate  the  pectoralis  major  from 
the  furcula.  From  the  posterior  end  of  the 
keel  continue  the  cut  laterally  to  separate  the 
muscle  from  the  body  of  the  sternum.  With 
the  handle  of  a  scalpel  gently  separate  the 
pectoralis  major  from  the  pectoralis  minor  be- 
neath. 
Note: 

10.  The  pectoral  blood-vessels. 

11.  The  axillary  air-sac. 

12.  Note  the  oesophagus  passing  posteriorly  from 

the  crop. 

Cut  carefully  through  the  remaining  muscle  (pec- 
toralis secundus)  close  to  the  keel  of  the  sternum. 
With  strong  scissors  cut  through  the  body  of 
the  sternum  close  to  the  keel  •  cut  through  the 
furcula  and  cut  away  the  articulation  of  the 
coracoid  with  the  sternum. 


PIGEON.  119 

Reflect  the  two  sides  of   the  body-wall  and 
note  the  viscera  now  exposed  to  view : 

13.  The  heart  in  the  pericardium. 

14.  The  liver.     How  many  ]obes  has  it  ?     Which 

one  is  larger  ? 

15.  The    duodenum,    a   U-shaped    loop    of    the 

intestine. 

16.  The  pancreas,  lying  between  the  limbs  of  the 

loop.     Look  for  its  ducts. 

17.  The  gizzard. 

18.  The  loops  of  the  small  intestine. 

19.  The  epigastric  vein,  carrying  blood  from  the 

omentum  and  passing  up  in  the  falciform 
ligament  to  the  anterior  border  of  the 
liver. 

(Note  :    20  and  21  should  be  left  until  after 
III.) 

20.  Unravel  the  intestine  and  observe  : 
(Esophagus.  Intestine. 

Crop.  Rectum  and  rectal  coeca. 

Proventriculus.         Liver. 
Gizzard .  Pancreas. 

Spleen. 
Diagram  of  the  abdominal  viscera,  ducts,  etc. ! 

21.  Cut  open  the  gizzard  and  observe  its  struc- 

ture. 
III.  The  Circulatory  System. 

The  Heart. 
Open  the  pericardium  and  observe  the  heart : 


120  GENERAL  BIOLOGY. 

Auricles. 
Ventricles. 
Diagram  ! 
The  Veins. 

A.  The  anterior  venae  cavae,  one  on  each  side  open- 

ing  into  the   right   auricle ;   formed   by    the 
union  of : 

1.  The  jugular  vein,  bringing  back  blood  from 

the  head  and  neck,  receiving : 
(a)  The  vertebral  vein. 

2.  The  brachial  vein,  bringing  blood  from  the 

wing. 

3.  The  pectoral  vein,  bringing  blood  from    the 

chest  muscles. 

B.  The  posterior  vena  cava,  an  unpaired  vein,  open- 

ing into  the  right  auricle;  formed  by  : 
1.  The  two  iliac  veins.     Each  iliac  vein  begins 
near  the  anterior  end  of  the  kidney  by  the 
union  of : 

(a)  The  femoral  vein,  bringing  blood  from  the 

leg. 

(b)  The  hypogastric  vein,  passing  through  the 

kidney  and  formed  in  the  posterior 
abdominal  region  by  the  union  of : 

(oa)  The  caudal  vein,  an  unpaired  vein 
from  the  tail. 

(bb)  The  internal  iliac  vein  from  the  pelvis. 

(cc)  The  posterior  mesenteric  vein  (coccygeo 


PIGEON.  121 

mesenteric),  an  unpaired  vein  from 
the  lower  part  of  the  intestine. 
(dd)  The  sciatic  vein,  from  the  leg  ;  open- 
ing into  the  hypogastric  vein  near 
the  junction  of  the  middle  and  pos- 
terior lobes  of  the  kidney, 
(c)  The  renal  veins,  bringing  blood  from  the 
kidneys,  a  larger   vein    from    the   pos 
terior  lobes,  and  a  smaller  vein  from 
the  anterior  lobe. 

2.  The  hepatic  veins  from  the  liver  ;  they  join 
the   post  cava  near  its  entrance  into  the 
right  auricle. 
O.  The  hepatic  portal  system. 

1.  The   gastric  veins,  two  small  veins  from  the 

left  side  of  the  gizzard  to  the  left  lobe  of 
the  liver. 

2.  The   portal  vein,   sending  a  branch  into  the 

right  and  a  branch  into  the  left  lobe  of  the 
liver,  formed  by : 

(a)  The  gastro-duodenal  vein   from    the  right 

side  of  the  gizzard,  duodenum,  pancreas, 
etc. 

(b)  The  anterior  mesenteric  vein,  from  most  of 

the  small  intestine. 

(c)  The  posterior  mesenteric  vein  from  the  large 

intestine,  etc. 

The  portal  vein  receives  blood  through  a  small 
vein  from  the  spleen. 


122  GENERAL  BIOLOGY. 

D.   The  pulmonary  veins,  short  veins  from  the  lungs 

which  unite  and  open  into  the  left  auricle. 
Diagram  of  the  veins  ! 
The  Arteries. 

A.  One  aortic  arch,  the  aorta,  which  passes  to  the 
right.     It  gives  off: 

1.  The    innominate   arteries,  one   on    each  side, 

giving  rise  to : 

(a)  The  common  carotid  artery,  to  the  head. 

(b)  The   subclavian   artery,  which   divides   to 

form  : 

(ad)  The  brachial  artery,  to  the  wing. 
(bb)  The  pectoral  artery,  to  the  muscles  of 
the  chest. 

2.  The  dorsal    aorta,   which    passes   posteriorly 

dorsal  to  the  heart. 
It  gives  off : 

(a)  The  coeliac  artery,  unpaired,   to  the  pro- 

ventriculus,  gizzard,    spleen,  pancreas, 
duodenum,  etc. 

(b)  The    anterior  mesenteric  artery,    unpaired, 

to  the  rest  of  the  small  intestine. 

(c)  The  anterior  renal  arteries,  paired. 

(d)  The  femoral  arteries,  paired. 

(e)  The   sciatic  arteries,  paired.     The  sciatic 

artery  of  each  side  gives  off : 
(aa)  The  middle  and  posterior  renal  arteries. 
(/)  The  posterior  mesenteric  artery,  unpaired, 
to  the  large  intestine. 


PIGEON.  123 

(g)  The  internal  iliacs,  paired,  to  the  pelvis. 
(h)  The  caudal  artery,  the  posterior  continua- 
tion of  the  dorsal  aorta. 
B.  The  pulmonary  artries,  to  the  lungs. 

Diagram  of  the  arteries  ! 
N.  B.— Keturn  here  to  II.  17  and  18. 

IV.  The  Excretory  and  Eeproductive  Organs. 

Carefully  remove  the  digestive  organs,  cu^ng 
through  the  intestine  about  an  inch  from  its 
posterior  end. 

1.  The  ovaries  and  oviducts,   or  testes  and 

vasa  deferentia. 

2.  The  kidneys,  adrenal  bodies,  ureters. 

3.  The  cloaca. 

Slit  open  the  rectum  on  the  ventral  side  and 
continue  the  cut  into  the  cloaca. 

(a)  Note    the   number   of    chambers   into 

which  the  cloaca  is  divided. 

(b)  Find  the    openings    of  the   ureters  on 

the  dorsal  side  of  the  cloaca  in  the 
urino-genital  pouch.     Also,  the  open- 
ings of  the  genital  ducts. 
Diagram  of  excretory  and  reproductive  organs  ! 

V.  The  Nervous  System. 

A.  The  Sympathetic  Nervous  System. 

1.  A  delicate  cord  running  on  each  side  close 
to  the  vertebral  column,  with  ganglia  at 
intervals. 


124  GENERAL  BIOLOGY. 

Diagram  ! 

B.  The  Peripheral  Nervous  System. 

1.  On  the  dorsal  wall  of  the  body-cavity  note : 

the  thoracic  spinal  nerves  coming  from  be- 
tween the  vertebrae  and  passing  out  between 
the  ribs. 

2.  The   brachial   plexus,  a  network  of  nerves  at 

the  base  of  the  neck.  Trace  the  distribu- 
tion of  the  chief  nerves  given  off  from  it. 

3.  The    lumbar  plexus    in    the    lumbar   region. 

Two  nerves  are  given  off  from  it ;  what  do 
they  innervate  ? 

4.  The  sciatic  plexus.     The  sciatic  nerve  is  given 

off ;  what  is  its  course  ? 
Diagram  ! 

C.  The  Brain. 

1.  Externals. 

As  the  brain  lies  in  the  cranial  cavity,  note : 
(a)  The  cerebral  hemispheres. 
(6)  The  olfactory  nerves. 

(c)  The  optic  lobes. 

(d)  The  cerebellum. 

(e)  The  medulla  oblongata. 
Diagram  ! 

JZemove  the  dorsal  arches  of  the  first  two  verte- 
brce,   cut  through  the  spinal  cord,  and  turn 
the  brain  forward,  carefully  cutting   all   the 
•nerves. 
On  the  ventral  side  note : 


PIGEON.  125 

(/)  The  optic  cliiasma. 

(g)  The  infundibulum. 

(h)  The  pituitary  body. 
Diagram  ! 
2.  Section. 

(a)  Gently  press  apart  the  hemispheres  ;  note 

that  they  are  not  connected. 
Make  a  shallow  incision  in  the  inner  wall  of  one 
of  the  hemispheres  near  its  poster  o- dor  sal 
corner  so  as  to  open  its  cavity.  Carefully  cut 
away  enough  of  the  inner  end  of  the  posterior 
wall  to  see  the  whole  of  the  cavity. 

(b)  Note  the  cavity  of  the  cerebral  hemisphere : 

the  lateral  ventricle.    Its  floor  is  formed 
by  the  corpus  striatum. 

Remove   the    cerebellum   by   cutting  through   its 
peduncles. 

(c)  Note  : 

(aa)  The   two   optic  lobes  connected  by 

the  optic  commissure. 
(bb)  Anterior  to  the  optic  lobes  the  paired 

optic  thalami. 
(oc)  Between  the  optic  thalami  the  third 

ventricle. 
(dd)  Anterior  to  the  optic  thalami  is  the 

anterior  commissure,  and  posterior 

to  them  is  the  posterior  commissure. 
(ee)  Posterior  to  the  optic  commissure  is 

the  fourth  ventricle. 


126  GENERAL  BIOLOGY. 

(ff)  At  each  side  of  the  fourth  ventricle 
are  the  peduncles  of  the  cerebel- 
lum. 
(d)  Cut  off  the  dorsal  wall  of  one  optic  lobe 

and  see  its  ventricle. 

(e)  Make  a  median  (vertical)  longitudinal  sec- 
tion of  the  brain  and  see  the  continuity 
of  the  third  and  fourth  ventricles. 
Diagram! 

VI.  The  eye. 

Divide  one  into  two  lateral  halves,  and  the  other 

into  anterior  and  posterior  halves. 
Observe  : 

1.  The  two  humors. 

2.  The  sclerotic  coat. 

3.  The  choroid  coat. 

4.  The  retina. 

5.  The  ora  serrata. 

6.  The  entrance  of  the  optic  nerve. 

7.  The  pecten. 

8.  The  ciliary  processes. 

9.  The  lens. 

10.  The  iris. 

11.  The  pupil. 

VII.  The  Feather. 

In  a  tail  feather,  note  : 
1.  The  stem  (scapus),  consisting  of : 

(a)  The  quill  (calamus),  the  hollow  proximal 
part. 


PIGEON.  127 

(b)  The  shaft  (rachis),  the  solid  distal  part. 

2.  The  vane  (vexillum),  made  up  of  barbs. 

3.  The  inferior  and  the  superior  umbilicus. 

Cut  off  a  piece  of  the  vexillum,  socik   it  for  a 
few  minutes  in  a    small   dish  of  alcohol  to 
remove  the  air,  and  examine  in  glycerine  under 
a  high  power. 
Note  the  barbs,  barbules,  and  barbicels.     What 

is  the  relation  between  the  barbules   and 

the  barbicels  ? 
Sketch,   noting  which   is   the  proximal    and 

which  the  distal  side  ? 


RABBIT. 

I.  External  Characters. 

1.  The  body  consisting  of  : 
(a)  The  head  with  : 

(act)  The  mouth ;   note  the  character  of 

the  lips. 
(bb)   The  nostrils  ;  note  their  relation  to 

the  upper  lip. 

(cc)   The  vibrissse,  or  whiskers. 
(del)  The  ears,  with  elongated  pinnae. 
(6)  The  neck, — short  and  thick. 

(c)  The  trunk',  made  up  of  : 

(aa)  The  thorax,   the    anterior  part,  pro- 
tected by  bony  structures. 
(bb)  The    abdomen,  the    posterior    part, 
with  soft  walls.     Its  openings  are  : 
(aaa)  The   urino-genital   opening   in 
the  median  line,  lying  near : 
(bbb]    The  anus,  also  in  the  median 
line,  posterior  to  the  urino- 
genital  opening. 

Note  in  the  female  the  mammae  or  teats,  four 
or  five  pairs  on  each  side,  near  the  ventral 
median  line. 

In  the  male,  slightly  anterior  to  and  at  the 
sides  of  the  reproductive  opening,  the 
scrotal  sacs. 

(d)  The  tail. 

2.  The  fore  and  hind  limbs. 

128 


RABBIT.  129 

Each  divided  into  three  chief  regions. 
Count  the  number  of  digits. 
II.  Abdominal  Yiscera. 

Spread  the  animal  out  dorsal  side  dotvn  with  its 
head  hanging  over  the  edge  of  the  pan,  and 
fasten  it  down  by  the  legs. 

Make  a  shallow  cut  along  the  median  ventral  line 
and  skin  the  ventral  and  lateral  regions  of  the 
abdomen  and  thorax.  (The  skinning  to  be  com- 
pleted later.)  Open  the  abdominal  cavity  by  a  cut 
in  the  median  ventral  line. 

1.  What  forms  the  anterior  wall  of  the  abdomi- 

nal cavity  ? 

2.  Identify  the   organs    exposed  to  view ;   e.g., 

the  stomach,  the  liver,  the  intestine,  etc. 
Pass  a  single  ligature  around  the  oesophagus 
near  the  cardiac  end  of  the  stomach^  and  double 
ligatures  around  the  rectum  about  two  inches 
from  the  anus.  Find  the  portal  veint  and  double- 
ligature  it  at  a  little  distance  from  the  liver.  (So 
that  later  the  intestine  may  be  taken  out.) 

3.  Examine  the  intestine. 
(a)  In  place,  finding  : 

(aa)  The  pancreas  and  duct. 

The  pancreas  consists  of  a  number 

of    scattered    masses  lying  in  the 

mesentery  of  the  duodenum.     Its 

•     duct  opens  into  the  ascending  loop 

of  the   duodenum,   and  is  formed 


130  GENERAL  BIOLOGY. 

by  the  union  of  numerous  smaller 
ducts  from  the  different  lobes  of 
the  pancreas. 

(bb)  The    gall-bladder    and    the    common 

bile-duct.      The    gall-bladder    lies 

posterior  to  one  of  the  lobes  of  the 

right  side   of  the  liver.     Its  duct 

unites  with  a  duct  from  each  lobe 

of  the  liver  to  form  the  common 

bile  -  duct,    which   opens   into   the 

duodenum  close  to  the  pylorus. 

(6)  Eemove  the  intestine  (for  directions  see 

the  next  following  italicized  paragraph) 

and  unravel  and  identify  its  different 

parts.     Diagrams !     In  taking  out  the 

intestine  note  the   attachment   of   the 

mesentery  to  the  intestine  and  to  the 

body -wall.     Compare  its  extent  in  one 

of  these  regions  with  its  extent  in  the 

other. 

To  remove  the  intestine   cut  above  the  ligature  on 
'the  oesophagus  and  between  the  double  ligatures. 
Ligature   any  large   vein  that   it  is  needful   to 
cut  through.     Be  careful  not  to  injure  the  repro- 
ductive organs. 

Remove  the  eyes,  carefully  t  with  the  muscles   and 
put  tliem  into  formic  aldehyde  solution  ( 1  to  2 
per  cent.). 
Skin   the  headt  ligature   the  vessels   of  the   neck, 


BABBIT.  131 

and  cut  off  the  head.  Open  the  skull  to  expose 
the  cerebrum  and  most  of  the  cerebellum.  Put 
the  head  into  formic  aldehyde  solution  (1  to  2 
per  cent.). 

Finish  skinning  the  body  (leaving  the  skin  intact 
in  the  region  of  the  anus  and  the  scrotal  sacs). 

III.  The  Thoracic  Cavity. 

Open  the  thorax  without  injuring  the  diaphragm  by 
a  slit  on  each  side  of  the  sternum.  Remove  the 
sternum. 

1.  Examine    the    structure    of    the    diaphragm 

(muscle,  tendon). 

2.  Insert  a  blowpipe  into  the  trachea  and  blow 

up  the  lungs. 

IV.  The  Circulatory  System. 

Open  and  cut  away  the  pericardium.  Dissect  off 
the  fat  and  the  connective  tissue  around  the  heart 
and  the  vessels  near  to  it. 

In  young  animals  the  fat-like  thymus  gland  is 
very  conspicuous  in  the  anterior  end  of  the 
thorax,  and  sometimes  it  lies  over  the  anterior 
end  of  the  heart. 
Find  the  parts  of  the  heart : 
The  right  and  left  auricles. 
The  right  and  left  ventricles.     (If  no  division- 
line  can  be  seen,  try  to  distinguish  the  two 
ventricles  by  feeling  the  thickness  of  their 
walls.) 


132  GENERAL  BIOLOGY. 

A.  The  Veins. 

Leave  those  in  the  posterior  abdominal  region 
until  after  the  reproductive  organs,  etc ,  have 
been  examined. 
I.  The  Yense  Cavse. 

A  diagram  should  be  begun  at  an  early  stage  in 
the  dissection  of  the  veins,  etc.,  and  added  to 
as  each  new  structure  is  seen. 

The  anterior  venae  cavse. 

Opening  into  the  right  auricle  the  right  anterior 
vena  cava,  a  large  vein  bringing  blood  from  the 
right  arm  and  the  right  side  of  the  head,  etc. 
It  receives  near  the  heart  (best  seen  by  turn- 
ing the  heart  over  to  the  left) : 

1.  The  azygos  vein  which  comes  from  the  median 

dorsal  thoracic  region,  bringing  blood  from 
the  posterior  intercostal  spaces  of  both 
right  and  left  sides  of  the  body. 

2.  Near  the  entrance  of  the  azygos    a  smaller 

vein,  the  right  intercostal  vein,  bringing 
blood  from  the  right  anterior  intercostal 
region. 

3.  Anterior  to  the  intercostal  vein  a  vertebral  vein 

from  the  brain  and  the  spinal  cord. 
4  A  small  vein  from  the  inner  side  of  the  ven- 
tral wall  of  the  thorax,  the  internal  mam- 
mary vein.  Near  the  entrance  of  the  in- 
ternal mammary  vein  the  anterior  vena 
cava  is  formed  by  the  union  of  : 


RABBIT.  133 

5.  The   subclavian  vein,  a  large   vein  from    the 

arm  and  shoulder,  with  : 

6.  The  external  jugular  vein,  from  the  superficial 

parts  of  the  head.  The  external  jugular 
vein  near  its  union  with  the  subclavian 
vein  receives  : 

(a)  The  internal  jugular  vein  from  the  brain. 
The  left  anterior  vena  cava,  like  the  right    an- 
terior  vena    cava,  except   that  it  receives  a 
small  coronary  vein    from    the  walls    of    the 
heart,  and   does   not  receive   an  azygos  vein. 
The  posterior  vena  cava,  a  large  vein  that  empties 
into  the  right  auricle.     It  receives  near  the 
heart : 

1.  The  hepatic  veins  from  the  lobes  of  the  liver. 

2.  Veins  from  the  body-wall,  one  on  each  side, 

entering  the  posterior  cava  close  to  or  in 
connection  with  : 

3.  The  renal  veins  from  the  kidneys,  one  on  each 

side. 

4  The  spermatic  (or  ovarian)  veins  from  the  re- 
productive organs. 

The  veins  posterior  to  the  spermatic  veins 
should  be  left  until  after  the  examination 
of  the  reproductive  organs,  etc. 

5.  The  ilio-lumbar  veins  from  the  posterior  body- 
wall.  The  left  ilio-lumbar  vein  in  some 
rabbits  does  not  enter  the  posterior  cava 
at  the  same  level  with  its  fellow  of  the  op- 


134  GENERAL  BIOLOGY. 

posite  side,  but  runs  anteriorly  to  about 
the  level  of  the  left  renal  vein.  In  this 
case  the  left  spermatic  vein  empties  into 
the  ilio-lumbar  vein. 

6.  The  external  iliac  veins,  bringing  blood  from 

the  legs,  from  the  bladder,  and  in  the 
female  from  the  uterus. 

7.  The  internal  iliac  veins,  which  by  their  union 

form  the  posterior  vena  cava.  They  bring 
blood  from  the  postero-dorsal  part  of  the 
thighs. 

II.  The  Portal  System. 

The  portal  vein  enters  the  liver  by  a  branch 
to  each  lobe.  (It  is  formed  by  veins  from 
the  stomach,  from  the  different  regions  of 
the  intestine,  and  from  the  spleen.) 

III.  The  Pulmonary  Veins. 

(These  are  best   seen  when  taking   out  the 
heart  and  lungs,  IV.  C.)     Two  veins  from 
each  lung  which  enter  the  dorsal  side  of 
the  left  auricle. 
B.  The  Arteries. 

I.  The  aortic  arch,  arising  from  the  left  ventricle 
and  curving  to  the  left  to  form  in  the  median 
dorsal  line  the  dorsal  aorta. 
The  aorta  gives  off  the  following  arteries  : 
1.  Near  the  beginning  of  the  arch,  a  vessel  to 
the  right,  the  innominate  artery,  which  soon 
divides  to  form  : 


RABBIT.  135 

(a)  The  right  subclavian  artery.      It  divides 

into  : 

(aa)  The  vertebral  artery  which  passes 
dorsally  and  toward  the  median 
line. 

(bb)  The  internal  mammary  artery  to  the 
inner  wall  of  the  thorax.    It  sends 
off  five  branches  to  the  five  ante- 
rior intercostal  spaces. 
(cc)  The  brachial  artery  to  the  arm. 
(b)  The  right  common  carotid  artery. 

2.  The  left  common  carotid  artery,  on  the  left  of 

the  median  line.     (Not  infrequently  united 
with  1.) 

3.  The  left  subclavian  artery. 

Its  branches  like  those  of  the  right  side. 

4.  The   thoracic   arteries ;    seven    pairs    to    the 

seven  posterior  intercostal  spaces. 

5.  A  little  posterior  to  the  diaphragm,  the  large 

unpaired  coeliac  artery  to  the  liver,  the  stom- 
ach and  the  spleen. 

6.  The  anterior   mesenteric  artery  to  the  small 

intestine,  the  pancreas,  the  coecum  and  the 
colon.     It  arises  near  the  coeliac  artery. 

7.  The  renal  arteries,  paired,  to  the  kidneys. 

8.  The  spermatic  or  ovarian  arteries  to  the  repro- 

ductive organs. 

(The   arteries    posterior    to    the    spermatic, 
etc.,  arteries  should  be  left  until  after  the 


136  GENERAL  BIOLOGY. 

examination   of   the    reproductive    organs, 
etc.) 

9.  The   posterior  mesenteric  artery,  unpaired,  to 
the  rectum. 

10.  The  sacral  artery  from  the  dorsal  side  of  the 

dorsal  aorta,  unpaired,  to  the  tail. 

11.  The  iliac  arteries,  the  two  branches  into  which 

the  dorsal  aorta  divides   at   its   posterior 
end.     Each  of  these  gives  off: 

(a)  The  ilio-lumbar  artery  to  the    body-wall, 

and  divides  into : 

(b)  The  internal  iliac  artery,  to  the  pelvis. 

(c)  The  external  iliac  artery,  which  gives  off 

an  artery  to  the  bladder  and  becomes 
the  femoral  artery  to  the  hind  leg. 
II.  The  Pulmonary  Artery. 

(These  are  best  seen  when  taking  out  the 

heart  and  lungs.     IY.  C.). 
From  the  ventral  side  of  the  right  ventricle 
a  vessel  passes  anteriorly,  and,  curving 
around  the  dorsal  side  of  the  heart,  divides 
into  right  and  left  branches  to  the  right 
and  left  lungs. 
Diagrams  ! 

C.  The  heart.     Find  its  parts  again ;  then  liga- 
ture   the    posterior   vena    cava   near   the 
heart  and  take  out  the  heart. 
To  remove  the  heart  cut  through  all  the  veins  and 
arteries  (leaving  the  ends  attached  to  the  heart 


EABBIT.  137 

as  long  as  possible]  except  those  connected  with 
the  lungs.  Take  out  heart  and  lungs  and  put 
them  into  a  dish  of  ivater. 

1.  Identify  again  the  vessels  entering  and  leav- 

ing the  heart. 

Cut  aivay  the  outer  walls  of  both  auricles  and  wash 
out  the  Hood. 

2.  See  the  septum  with  the  fossa  ovalis,  and  the 

entering  veins. 

Make  with  fine  scissors  a  cut  through  the  ventral 
wall  of  the  pulmonary  artery  and  continue  it 
through  the  wall  of  the  right  ventricle. 

Note  : 

3.  The  auriculo-ventricular  (tricuspid)  valve. 

4.  The  ventricular  septum. 

5.  The    semilunar    valves    at  the    base    of   the 

pulmonary  artery. 

6.  Cut  away  the  outer  wall  of  the  left  ventricle 

and  compare  its  thickness  with  that  of  the 
right  ventricle. 
Note  in  the  left  ventricle  : 

7.  The  auriculo-ventricular  (mitral)  valve. 

8.  The  chordae  tendinese. 

9.  The  papillary  muscles. 

10.  Compare  7,  8,  and  9  with  the  corresponding 

structures  in  the  right  ventricle. 
Note  : 

11.  The  semilunar  valves  at  the  beginning  of  the 

aortic  arch. 


138  GENERAL  BIOLOGY. 

V.  The  Excretory  Organs. 

1.  Note  the  shape  and  position  of  the  kidneys. 

2.  Trace  the  ureter  from  kidney  to  bladder. 

3.  Find  the  adrenal  bodies. 

4.  Take  out  the  kidneys.     Cut  one  kidney  into 

halves  lengthwise  and  horizontally,  and  the 
other  into  halves  transversely  (correspond- 
ing to  these  planes  as  the  organs  lay  in  the 
body). 
Note: 

(a)  The  cortex. 

(b)  The  medulla. 

(c)  The  pelvic  cavity. 
Diagrams  ! 

VI    The  Reproductive  Organs. 

1.  Identify  ovaries  or  testis  (position  best  found 
by  following  out  the  spermatic  artery  or 
vein). 

(a)  Ovary :    note    the    Fallopian    tube    and 

funnel,  the  uterus,  and  the  vagina. 

(b)  Testis  :  note  its  relation  to  the  scrotal  sac. 

Carefully   slit   open    one    scrotal    sac. 

Look  for  the  epididymis.     Trace  the  vas 

deferens. 

With  bone  forceps  or  knife  cut  through  the 
symphysis  pubis.  In  the  female  open  the  vagina 
just  below  the  uteri  by  a  lateral  cut,  and  continue 
this  to  the  external  opening. 


RABBIT.  139 

(c)  Find  the  urethra  and  open  it  to  the  blad- 

der. 

(d)  Note  the  orifices  of  the  ureters. 

(e)  Examine  the  openings  of  the  uteri  and  slit 

one  open. 

In  the  male  open  the  urethra  by  a  cut  beginning  at 
the  external  opening  and  continue  the  cut  to  the 
bladder. 

(/}  Observe  the  uterus  masculinus. 
(g)  Note  the  relation  of  the  vasa  deferentia  to 

the  ureters. 

Make  a  diagram  of  a  view  from  the  side  show- 
ing   the    relations    of    ureter,    bladder,   vas 
deferens  (oviduct),  urethra  (vagina). 
VII.  Find  the  veins  and  arteries  of  the  posterior 
abdominal  region  and  trace  those  of  one 
side  into  the  leg. 
VIII.  Review  the  lobes  and  vessels  of  the  liver  and 

take  it  out. 
The  Nervous  System. 

A.  The  Sympathetic  Nervous  System. 

A  chain  of  ganglia  extending  from  head  to 
tail  close  to  the  vertebral  column. 
Kami  communicantes  connect  them  with 
the  spinal  nerves.  The  ganglia  of  one 
side  are  also  connected  by  commissures 
with  those  of  the  other  side. 

B.  The  Peripheral  Nervous  System,  nerves 

passing  out  from  the  brain   and  from 


140  GENERAL  BIOLOGY. 

the  spinal  cord.     Note  especially  at  the  level 
of  the  shoulder  : 

1.  The  brachial  plexus,  made  up  of  the  5th  to 

the  8th  cervical  and  the  1st  thoracic  nerves 
inclusive.     It  gives  off  four  chief  nerves ; 
follow  them  out  and  see  what  regions  they 
innervate. 
In  the  region  of  the  leg  : 

2.  The  lumbro-sacral  plexus,  made  up  of   the 

5th  to  the  7th  lumbar  and  of  the  1st  to  the 
3d    sacral   nerves,  inclusive.     It   gives   off 
three  chief  nerves  ;  follow  them  out. 
C.  The  Brain. 
1.  Externals. 

With  bone  forceps  cut  away  as  much  of  the  skull 
as    may  be  necessary  to  free  the  brain.     Take 
it  out  and  put  it  into  a  dish  of  formic  aldehyde 
solution  or  of  alcohol. 
Find  the  parts  visible  on  the  surface. 
On  the  dorsal  side  : 

(a)  The  olfactory  lobes. 

(b)  The  cerebral  hemispheres. 

(c)  The  pineal  gland. 

(d)  The  cerebellum. 

(e)  The  medulla,  etc. 
On  the  ventral  side : 

(a)  The  olfactory  lobes. 

(b)  The  cerebral  hemispheres. 

(c)  The  optic  nerves,  chiasma,  and  tracts. 


RABBIT.  141 

(d)  The  pituitary  body. 

(e)  The  corpus  mammillare. 
(/)  The  crura  cerebri. 

(g)  The  pons  Varolii. 

(h)  The  cerebellum. 

(i)    The  ventral  pyramids. 

(k)  The  medulla. 

Sketch  the  dorsal  and  the  ventral  aspect. 
2.  Section. 
Remove  the  right  half  of  the  cerebellum  by  a  median 

longitudinal  cut. 

(a)  See  the  relation  of  the  parts  beneath  (4th 

ventricle,  corpora  quadrigemina)  with- 
out further  cutting. 
Remove  the  other  half  of  the  cerebellum. 

(b)  The  cerebrum. 

Make  a  horizontal  cut  in  the  right  hemisphere  to 
expose  the  lateral  ventricle. 

Observe  the  hippocampus  and  see  the  succes- 
sion of  the  optic  thalami,  the  corpora  quad- 
rigemina, the  third  and  fourth  ventricles. 

(c)  The  cerebrum,  left  hemisphere. 

Make  a  frontal  section  half -ivay  from  front  to  back, 
or  cut  off  a  series  of  thin  sections  until  the  same 

<AJ  */ 

region   is  reached,  and  observe  again  the  same 
parts. 
X.  The  eye. 

Divide  one  into  two  lateral  halves  and  the  other 
into  anterior  and  posterior  halves. 


.  >    .    • 


142  GENERAL  BIOLOGY. 

Find: 

1.  The  sclerotic  coat.  7.  The  tapetum. 

2.  The  choroid  coat.  8.  The  lens. 

3.  The  retina.  9.  The  iris. 

4.  The  ora  serrata.  10.  The  pupil. 

5.  The  ciliary  processes.      11.  The  humors. 

6.  The  blind  spot. 

XI.  1.  The  Ear.     Identify  as  much  as  possible. 

2.  The  Teeth,,     Examine,  their  fgrm^osition,  *  ••-  ^ 


1.  Hip  and  knee.     Cut  into  them  arrfl  see 

construction. 

2.  Kemove  the  muscle,  etc.,  fro)ii  two  cervical 

vertebrae  and  examine  their  articulation. 


EMBRYOLOGY. 
FBOG. 

I.  Two-,  four-,  and  eight-celled  stages.* 

Study  in  a  watch-glass  with  a  hand-lens.  Do 
not  touch  the  eggs  ;  if  it  is  necessary  to  turn 
them  over,  do  so  with  a  stream  from  a  pipette  or 
roll  them  over  ly  tipping  the  watch-glass. 

Make  three  sketches  of  each  stage  : 

1.  From  the  dark  pole. 

2.  From  the  light  pole. 

3.  From  the  side  half-way  between  1  and  2. 

II.  Gastrula,  surface  view.     Three  stages. 
Examine  as  in  I. 

Note  the  formation  of  the  blastopore. 
Sketch. 

III.  Blastula.     Prepared  section.     /Sketch. 
Study  with  microscope. 

IY.  Gastrula.     Prepared  section.     Sketch. 

Study  with  microscope. 

Y.  Closure  of  the  blastopore  and  the  formation  and 
closure  of  the  medullary  folds.  Two  stages. 
Sketch. 

Study  in  a  watch-glass  with  a  hand-lens. 
VI.  The  appearance  of  the  adhesive  glands,  the  eyes, 
the  nasal  pits,  the  mouth,  and  the  gills  ;  and 
the  formation  of  the  operculum.    Four  stages, 
Sketch. 

*  When  preserved  in  a  dilute  aqueous  solution  of  formic  alde- 
hyde (1-2  per  cent.,  see  page  95)  the  egg-membranes  retain  their 
transparency  and  the  egg  has  a  perfectly  normal  appearance. 

143 


144  GENERAL  BIOLOGY. 

Study  in  a  watch-glass  with  a  hand-lens. 

VII.  Observe  the  circulation  in  the  gills  of  a  living 

tadpole. 

Examine  in  a  little  water  in  a  watch-glass  with 
microscope ,  AA  2. 

VIII.  The    early    embryo.      Prepared    transverse 

section.     Study  with  AA  2  and  D  2. 

1.  The  ectoblast  (two-layered). 

2.  The  neural  tube. 

3.  The  notochord. 

4.  The  archenteron. 

5.  The  mesoblast. 

(a)  Somatic. 

(b)  Splanchnic. 
Sketch,  much  enlarged. 

IX.  The  dissection  of  the  tadpole. 

Dissect  under  ivater.  Pin  the  tadpole,  dorsal  side 
down,  through  the  ba.se  of  the  tail  and  the  roof 
of  the  mouth. 

Observe  : 

1.  The  mouth  and  the  horny  teeth. 

2.  The  eyes.     Are  eyelids  present? 

3.  The  water-pore  from  the  branchial  chamber. 

On  which  side  is  the  pore  ? 

4.  The  anus. 

Open  the  abdomen  by  a  median  incision  of  the  ventral 

body-wall. 
Note: 

5.  The  coiled  intestine.     Uncoil  it. 


EMBRYOLOGY.  145 

6.  The  liver. 

7.  The  pancreas. 

8.  The  lungs. 

9.  The  heart. 

10.  The  kidneys,  pronephros  or  mesonephros. 

11.  The  reproductive  organs. 

Push  a  bristle  into  the  water-pore,  and  then  carefully 
open  the  branchial  chamber. 

12.  Examine  the  internal  gills  and  arches. 

13.  Count  the  number  of  arches. 

14.  Look  for  the  first  pair  of  feet. 

15.  Open  the  pericardium. 

16.  Find: 

(a)  The  ventricle. 

(6)  The  auricles. 

(c)  The  sinus  venosus  and  its  branches. 

(d)  The  aortic   bulb,  divided  into  two  parts 

and  each  of  these  again  into  three  parts. 
Trace  these  to  the  gill-arches.  Note 
that  the  branch  to  the  third  arch  divides 
again. 

Open  the  mouth  and  the  pharynx  by  a  ventral  longi- 
tudinal cut.     See  : 

17.  The  sieve -like  arrangement  of  the  gill-arches. 

18.  The  dorsal  aorta,  double  in  the  gill  region, 

one  on  each  side  receiving  the  vessels  from 
the  gills. 

19.  Find  the  posterior  feet. 

20.  Of  what  structures  is  the  tail  made  up  ? 


14:6  GENERAL  BIOLOGY. 

CHICK. 
I.  The  Egg. 

1.  Raw  egg. 

Holding  the  egg  in  the  left  hand  with  its  rounded 
end  toward  the  right,  make  a  small  opening  (by 
tapping  with  the  points  of  tJie  large  scissors)  in 
the  rounded  end. 
Note: 

(a)  The  shell. 

(b)  Two  membranes. 

(c)  The  air-space  between  the  two  membranes. 
With  large  scissors  cut  an  oval  piece  from  the  top 

of  the  shell. 

Look  in  and  identify  the  parts : 

(d)  The  white,  with  chalazse. 

(e)  The  yolk  with  the  blastoderm. 
Diagram  ! 

Enlarge  the  opening  and  gently  pour  the, egg  into  a 
dish. 
Does  the  yolk  mingle  with  the  white  ? 

2.  Boiled  egg. 

Remove  the  shell,  finding  again  the  mem- 
branes and  the  air-space. 

With  the  rounded  end  to  the  left  try  to  take 
off  the  white  by  unwinding  it  spirally  from 
left  to  right. 

Find  the  blastoderm.  With  a  razor  divide 
the  yolk  into  halves,  catting-  through  the 
middle  of  the  blastoderm.  Try  to  see  : 


EMBRYOLOGY.  147 

(/)  The  urn  in  the  centre, — its  neck  extend- 
ing to  the  blastoderm. 

(g)  The  alternate  layers  of  white  and  of  yel- 
low yolk. 
Diagram  1 

In  the  following  work  the  students  should 
leave  the  slides  in  the  trays  on  their  tables 
at  the  end  of  the  laboratory  period.  If  a 
particular  slide  is  wanted  again,  its  number 
should  be  entered  by  the  student  on  the 
card  that  is  hanging  up  for  the  purpose. 

II.  The  Unincubated  Blastoderm. 
Examine  first  tvith  A  A  2,  then  with  D  2. 

1.  Surface  view.     Observe  the  relative   size  of 

the  cells  in  the  middle  and  at  the  periphery. 

2.  Section. 

Sketch  with  D  2  the  cell-outlines  in  a  small  portion 
of  (1)  and  (2)  accurately,  and  on  a  large  scale. 

III.  The  Early  First  Day. 

1.  The  primitive  streak.     Surface  view. 
Study  with  AA  2.     Sketch  carefully. 

2.  The  medullary  folds.     Surface  view. 

Study  ivith  A  A  2,  then  with  D  2.    Sketch  carefully. 

3.  Sections : 

(a)  Primitive  streak.     (Single  section.) 

(b)  Medullary  folds.     (Single  section.) 

(c)  The   early  first   day    chick.       (Complete 

series.) 


148  GENERAL  BIOLOGY. 

Study  (a)  and  (6) ;  then  begin  at  the  posterior 
end  (why?)  of  (c),  and  going  toward  the 
anterior  find  the  regions  of  the  primitive 
streak  and  medullary  folds.  Observe  in 
the  medullary-fold  region  the  notochord 
and  the  mesoblast.  In  which  region  are 
the  medullary  folds  most  nearly  closed  ? 
After  studying  (c),  sketch  (a)  and  (b)  with  AA 
2,  after  having  examined  them  with  D  2. 
Sketch  the  outlines  of  the  different  germ- 
layers  with  a  black  pencil  and  fill  in  the 
space  between  with  faint  color,  using  al- 
ways the  same  color  for  the  same  germ- 
layer. 
IV.  The  Late  First  Day. 

1.  Surface.     Sketch  with  AA  2. 

2.  Sections. 

Begin  at  the  posterior  end  of  the  series. 
Observe  : 

(a)  The  primitive  streak. 

(b)  The  medullary  folds. 

(c)  The  mesoblast. 

Somatic  layer. 
Splanchnic  layer. 
Mesoblastic  somites. 

(d)  The  notochord. 

(e)  The  closure  of  the  medullary  folds  to  form 

the  neural  canal. 
(/}  The  closure  of  the  archenteron. 


EMBRYOLOGY.  149 

(g)  The  formation  of  the  head  by  lateral  and 

anterior  folds. 

Sketch  five  or  more  different  regions. 
V.  The  Second  Day. 

1.  Surface. 
Observe  : 

(a)  The  area  vasculosa. 

(b)  The  sinus  terminalis. 

(c)  The  amnion. 

(d)  The  vesicles  of  the  brain. 

(e)  The  eye. 
(/)  The  ear. 

(g)  The  lateral  outline  of  the  embryo. 

(h)  The  omphalo-mesenteric  veins  and  the  heart. 

(t)   The  dorsal  aortse  (?). 

After  studying  the  heart  and  veins  from  the 

dorsal  side,  turn  the  slide  over  and  examine 

the  ventral  aspect. 
Sketch  under  AA  2. 

2.  Sections. 

Beginning  at  the  posterior  end  observe  the 
structures  seen  in  the  first  day  (see  IV.  2. 
(a-g.),  and  In  addition  : 

(a)  The  Wolffian  ducts. 

(b)  The  dorsal  aortse. 

(c)  The  spinal  ganglia. 

(d)  The  omphalo-mesenteric  veins. 

(e)  The  heart. 

(/)  The  auditory  vesicles. 


150  GENERAL  BIOLOGY. 

(g)  The  aortic  arches.     What  is  their  relation 

to  the  pharynx  ? 
(h)  The  optic  vesicles. 
(i)   The  amnion. 
Sketch  six  different  regions. 
VI.  The  Third  Day. 

1.  Surface. 

Note    the   curvature    of   the   embryo;    upon 

which  side  does  it  lie  ? 
Note  the  cranial  flexure. 
Review  the  structures  seen  in  the  second  day 

and  observe  their  further  development. 
New  structures : 
(a)  The  anterior  vitelliue  vein.     What  is  the 

course  of  the  blood  within  it  ? 
(6)  The  gill-slits. 

(c)  The  lens  of  the  eye. 

(d)  The  nasal  pits. 

(e)  The  allantois.     (Possibly  not  yet  visible.) 
Sketch. 

2.  Sections. 

Begin  in  the  middle  region  (where  the  ar- 
chenteron  is  still  open).  Make  one  sketch. 
Then  work  backward  into  the  tail-fold  and 
make  out  its  structure  completely. 

Find  the  section  where  the  dorsal  aortse  pass 
out  into  the  area  vasculosa. 

What  is  the  origin  of  the  allantois  ? 
A.t  least  two  sketches  desirable. 


EMBRYOLOG  Y.  1 51 

Work  thence  forward  through  the  head-fold 
and  make  out  all  its  relations. 

Observe :  the  vitelline  veins,  the  ducts  of 
Cuvier,  the  heart  (follow  out  its  turns),  the 
pericardia!  cavity,  the  aortic  arches. 

Now  begin  at  the  front  end  of  the  series  and, 
remembering  the  cranial  flexure,  make  out 
the  various  parts  of  the  brain,  the  develop- 
ment of  the  eye,  the  internal  ear,  the  olfac- 
tory pits,  the  gill-slits  (in  the  neck  region), 
the  -  archenteron  and  its  derivatives :  the 
lungs,  the  liver,  and  the  pancreas  (?). 

Study  also  the  origin  of  the  cranial  nerves 

and  the  Wolffian  ducts  and  their  tubules. 
Sketches  to  show  these  structures. 
3.  The  living  embryo. 
With  the  points  of  strong  scissors  pierce  the  broad 

end  of  the    shell  to  allow  the  air  to   escape. 

Place  the  egg  in  warm  normal  salt  solution 

(38  degrees  (7.,)  cut  away  or  break  away  with 

forceps  the  upper  part  of  the  shell,  and  examine 

in  situ. 

Observe  ivith  a  hand-lens  : 

(a)  The  blastoderm  and  its  areas. 

(6)  The  position  and  form  of  the  embryo. 

(c)  The  heart,  etc. 
With  fine  sharp  scissors  cut  through  the  blastoderm 

entirely  around  the  outside  of  the  area  vascu- 

losa,  float  it  off  into  a  thin  watch-glass,  care- 


152  GENERAL  BIOLOGY. 

fully  remove  from  the  salt  solution,  and  exam- 
ine with  a  hand-lens  and  with  A  A  2. 
Study  at  first  the  circulation,  the   gill-slits, 
and   the    movements    of  the   heart.     Then 
review    as    far    as    possible    the    general 
anatomy. 
VII.  The  Fourth  Day. 

1.  The  formation  of  the  face. 
With  a  razor  cut  off  the  head  dose  "behind  the  last 
gill-slit.     With  fine  forceps  remove  the  parts 
of  the  heart,  etc. ,  that  are  attached  to  the  gill- 
region.    Fix  the  head,  dorsal  side  down,  in  a 
small  dish  of  alcohol,  and  with  a  hand-lens 
study  and     sketch    the    ventral    and    lateral 
aspects. 
Find: 

(a)  The  naso-frontal  process. 
(6)  The  nasal  pits. 

(c)  The  eyes. 

(d)  The  mouth. 

(e)  The  superior  maxillary  process. 
(/)  The  visceral  arches. 

What  structures  are  visible  in  section  on  the 

cut  surface. 
Till.  Older  Stages. 

Examine  for  the  amnion  and  the  allantois, 

and  for  the  development  of  the  face,  the 

limbs,  and  the  feathers,  and  for  the  changes 

of  the  yolk-stalk. 


INDEX. 


Abdomen,  67,  128 
Abdominal  ganglia,  73 
Adductor  muscles,  58,  59 
Adductor  muscle,  anterior,  59 
Adductor  muscle,  posterior,  59, 

61,65 

Adhesive  glands,  143 
Adrenal  bodies,  106,  123,  138 
Aerial  hyphae,  40 
Air-bladder,  114 
Air-bubbles,  6 
Air-sacs,  117, 118 
Air-space,  146 
Albumen,  146 
Aleuroue,  90,  91 
Alimentary  canal,  16,  17,  23 
Allantois,  150,  152 
Amaryllidacege,  86 
Amaryllideae,  86 
Amaryllis,  86 
Amnion,  149.  150,  152 
Ampelopsis  80,  81 
Anal  spot,  30,  33 
Augiosperm,  80 
Annual  rings,  79 
Annular  vessels,  81,  82 
Aunulus,  11,  43 
Antennae.  67,  74 
Autenuules,  67,  74 
Anterior  adductor  muscle,  59 
Anterior  commissure,  125 
Anterior  folds,  149 
Anterior  median  seminal  vesicle, 

19 
Anterior  nares,  96 


Anterior  retractor  muscle,  59 
Antero-posterior  differentiation, 

14 

Anther,  85 
Antheridium,  12,  77 
Antibrachium,  96,  129 
Anus,  15,  61,  67,  113,  128,  144 
Aortic  arches,  16,  103,  104,  150, 

151 

Aortic  bulb,  115,  145 
Aperture,  exhalent,  59 
Aperture,  inhalent,  59 
Appendages,  67,  73,  74 
Appendages,  pyloric,  114 
Aqueous  humor,  126,  142 
Archegonium,  12,  77 
Archenteron,  144,  148,  151 
Arches,  aortic,  16,  103,  104,  150, 

151 

Arches,  visceral,  152 
Area  vasculosa,  149,  150,  151 
Arteries  : 

abdominal  superior,  69 

antennary,  69 

aorta,  122,  134 

dorsal  aorta,  104, 115,  122,  123, 
134,  136,  145,  149,  150 

ventral  aorta,  115 

aortic  arches,  16,  103,  104, 150, 
151 

brachial,  122,  135 

carotid,  104 

carotid  arch,  104 

caudal,  123 

cephalic  circle,  115 

153 


154 


INDEX. 


Arteries,  cceliac,  104,  123,  135 

cceliaco-meseuteric,  104 

common  carotid,  122,  135 

cutaneous,  104 

femoral,  122,  136 

genital,  105 

hepatic,  69 

hypogastric,  105 

iliac,  136 

iliac  common,  105 

iliac  external,  136 

iliac  internal,  123,  136 

ilio-lumbar,  136 

innominate,  122,  134 

internal  mammary,  135 

lingual,  104 

mesenteric,  105 

mesenteric  anterior,  122,  135 

mesenteric  inferior,  105 

mesenteric  posterior,  123,  136 

ophthalmic,  69 

ovarian,  135 

pectoral,  122 

pulmonary,  123,  136 

pulmonary  arch,  104 

renal,  105,  122,  135 

sacral,  136 

sciatic,  105,  122 

spermatic,  135 

sternal,  69 

subclavian,  104,  122,  135 

thoracic,  135 

vertebral,  104,  135 
Ascospores,  37, 
Asexual  generation,  7,  77 
Auditory  openings,  67 
Auditory  vesicles,  149 
Auricle,    61,   65,    100,    115,  120, 

131,  145 

Auriculo-ventricular  valves,  137 
Axial  filament,  34 
Axial  strand,  76 
Axillary  air-sacs,  118 

Bacteria-cultures,  46,  47 
Barbicels,  127 
Barbs,  54,  127 


Barbules,  127 

Basic! ia,  40 

Bast-cells,  81 

Bast-fibres,  9 

Bast-vessels,  9 

Bean,  87,  90,  91,  92 

Bilateral  symmetry,  14  • 

Bile-duct,  100,  130 

Bladder,  99,  139 

Blastoderm,  146,  147,  151 

Blastopore,  143 

Blastula,  143 

Blind  spot,  126,  142 

Blood-vessel,  dorsal,  13,  16 

Body,  128 

Body-cavity,  16 

Body- wall,  16,  98 

Bojanus,  organ  of,  62,  65 

Brachial  nerve,  110 

Brachial  plexus,  110,  124,  140 

Brachium,  96,  129 

Brain,  107,  124,  140,  141 

Brain- cavities,  109 

Brain,  vesicles  of,  149, 151 

Branchiae,  60,  64,  65 

Branchial  chamber,  60,  65,  144 

Branchial  nerve,  62 

Branchio-cardiac  groove,  66 

Branchiostegites,  66 

Brownian  movement,  45 

Bubbles  of  air,  6 

Buccal  cavity,  97 

Buccal  pouch,  17,  21 

Buckwheat,  87,  88,  92 

Bud,  36,  53,  78,  82 

Bud-scales,  82,  83 

Bulbus,  115,  145 

Bundle,   fibro vascular,  8,   9,  10. 

79,  80,  81,  82 
Bundle-sheath,  9,  82 

Calamus,  126 
Calciferous  glands,  18,  19 
Calyptra,  77 
Calyx,  84,  85 
Cambium,  80 
Canal,  sternal,  72 


INDEX. 


155 


Capsule,  11,  77 

Capsulogenous  glands,  14 

Carapace,  66 

Castor-oil  beau,  87,  88,  91 

Cauda  equina,  108 

Caulicle,  89 

Cavities  of  brain,  109 

Cavity,  buccal,  97 

Cavity,  pericardial,  61,  62,  115 

Cell-division,  29 

Central  nervous  system,  20,  72, 

106 

Cephalic  circle,  115 
Cephalothorax,  66 
Cerebellum,  108,  124,  140,  141 
Cerebral  ganglia,  21,  23,  66 
Cerebral  hemispheres,  107,  108, 

109,  124,  125,  140,  141 
Cerebral  peduncles,  126 
Cerebro-splanchuic  commissure, 

63 

Cervical  groove.  66 
Chalaza,  87 
Chalazse.  146 

Chamber,  branchial,  60,  65 
Chamber,  cloacal,  60,  61 
Chamber,  suprabranchial,  60,  65 
Chemical   experiments,    32,   35, 

37 

Chloragogue  cells,  18 
Chordae  tendineae,  137 
Choroid  coat,  111,  126,  142 
Choroid  plexus,  108 
Chromatophore,  27,  29,  49 
Cilia,  30,  31,  32,  33,  34,  35 
Ciliary  processes,  126,  142 
Ciliated  rosettes,  19 
Circle,  cephalic,  115 
Circular  vessels,  17 
Circuino3sophageal  commissure, 

21,  23,  72 
Clitellum,  14 
Cloaca,  123 

Cloacal  chamber,  60,  61 
Cnidoblasts,  53,  55,  56 
Cnidocil,  53 
Coalom,  16 


Commissure  anterior,  125 
Commissure  cerebro-splanclmic, 

63 
Commissure  circuinoesophageal, 

21,  23,72 

Commissure  optic,  125 
Commissure  posterior,  125 
Conidia,  40 
Conidiophores,  40 
Conjugation,  35 
Connective,  85 

Contractile  vacuole,  24,  31,  34 
Conus,  115 
Cork,  80 
Cornea,  111 
Corolla,  84,  85 
Corpora  quadrigemina,  141 
Corpus  mammillare,  141 
Corpus  striatum,  125 
Cortex,  138 
Cortical  layer,  41,  42 
Cortical  parenchyma,  80 
Cotyledons,  88,  89,  92 
Coxopodite,  67 
Cranial  flexure,  150,  151 
Cranial  nerves,  151 
Crop,  17,  116,  119 
Crura  cerebri,  109,  141 
Crus,  96,  129 
Crystalloids,  91 
Cultures,  of  bacteria,  46,  47 
Currents  in  entoplasm,  31,  34 
Curvature  of  embryo,  150 
Cuticle,  16,  22,  30,  34,  66 
Cuvierian  ducts,  115,  151 

Daffodil,  86 
Dehiscence,  12 
Diaphragm,  131 
Dicotyledon,  80,  91 
Differentiation,  an tero- posterior, 

14 

Differentiation,  dorso-ventral,  14 
Digestive  gland,  65,  71 
Digits,  96,  129 
Disk,  33,  35 
Dissepiments,  16 


156 


INDEX. 


Division,  cell,  29 

Division,  endogenous,  28,  37 

Division,  nuclear,  94 

Dorsal  blood-vessel,  13,  16 

Dorsal  fissure,  108 

Dorsal  pores,  15 

Dorso- ventral  differentiation,  14 

Drops,  oil,  6 

Ducts  of  Cuvier,  115,  151 

Ducts,  Wolffian,  149,  151 

Duodenum,  99,  100,  119,  122, 129 

Dura  mater,  107 

Ear,  128,  142,  149,  151 
Early  embryo,  144 
Ectoblast,  144 
Ectoplasm,  24,  30,  34 
Egg,  146 
Egg-capsule,  22 
Egg-membranes,  143,  146 
Egg-shell,  146 
Elder,  82 

Embryo,  early,  144 
Endogenous  division,  28,  37 
Endopbragmal  skeleton,  72 
Endopbragmal  system,  72 
Endosperm,  88,  89 
Entoplasm,  24,  31,  34 
Entoplasm,  currents  in,  31,  34 
Epidermis,  7,  9,   10,  11,  75,  80, 

81,  83,  84 
Epididymis,  138 
Epipbragma,  78 
E  pis  tome,  33 
Erect  hyphae,  40 
Eustacbian  recesses,  97 
Excretory  openings,  61,  67,  139 
Exbalent  aperture,  59 
Exoskeleton.  66,  73 
Eye,  96,  111,  126,  141,  142,  143, 

144,  149,  150,  151,  152 
Eyelids,  96 

Face,  152 

Falciform  ligament,  117,  119 
Fallopian  tube,  138 
Fat-bodies,  100 


Fat-drops,  36,  40 

Feather,  126,  127 

Feathers,  arrangement  of,  116 

Feathers,  development  of,  152 

Feet,  145 

Femur,  96,  112,  129 

Fibrovascular    bundle,  8,  9,  10, 

11,  80,  81,  84 
Ficus  elastica,  83 
Filament,  85 
Filament,  axial,  34 
Filum  terminate,  108 
Fission,  35 
Fissure,  dorsal,  108 
Flagella,  29 
Folds,  anterior,  149 
Folds,  lateral,  149 
Folds,  medullary,  143,  147,  148 
Food-vacuoles,  24,  31,  34 
Foot,  52,  60,  65 
Foramen  of  Monro,  109 
Formalin,  95 

Formic  aldehyde,  95,  96,  143 
Fossa  oval  is,  137 
Fourth  ventricle,  125 
Frond,  7 
Frontal  spine,  66 
Fundamental  parenchyma,  8,  9, 

81,82 

Fuuiculus,  87 
Funnel,  19,  138 
Furcula,  118 

Gall-bladder,  99,  113,  130 
Ganglion,  cerebral,  21,  23,  63 

parieto-splanchuic,  02,  65 

pedal,  63 

spinal,  149 

subcesophageal,  21 

supracesophaii'eal,  72 

thoracic,  72 

visceral,  62,  65 
Gastric  teeth,  71 
Gastrocnernius  muscle,  111 
Gastrula,  143 
Gemmation,  37 
Generation  asexual,  7,  77 


INDEX. 


157 


Generation  sexual,  12,  75 
Genital  openings,  67 
Geranium,  84 

Gills,  60,  64,  65,  66,  73,  113 
Gills,  circulation  in,  144,  152 
Gills,  internal,  145 
Gill-arches,  145 
Gill-clefts,  113 
Gill-slits,  150,  151 
Gizzard,  17,  119,  122 
Gland-cells,  55 
Gland,  digestive,  65 
Gland,  pineal,  107,  140 
Glands,  adhesive,  143 
Glands,  calciferous,  18,  19 
Glands,  capsulogeuous,  14 
Glands,  green,  71 
Globoids,  91 
Glochidia,  64 
Glottis,  97,  99 
Gonidia.  42 
Gonidial  layer,  41 
Gray,  86 
Green  glands,  71 
Groove,  branchio-cardiac,  66 
Groove,  cervical,  66 
Guard-cells,  10,  11,  83 
Gymnosperin,  79 

Hay  infusion,  47 

Head,  96,  116,  128,  149 

Head-fold,  149, 151 

Heart,  61,  68,  98,  100,  114,  119, 

131,  136,  137,  145,  149,  151, 

152 

Hilum,  87 
Hip- joint  142 
Hippocampus,  141 
Horse-chestnut,  82 
Humor  aqueous,  126,  142 
Humor  vitreous,  111,  126,  142 
Hyacinth,  83 
Hydra  mridis,  53,  55 
Hyphae,  40,  42,  43,  44 
Hyphae  aerial,  40 
Hyphae  erect,  40 
Hypocotyl,  92 


Hypodermis,  16 
Hypostome,  52 

Indian  corn,  81,  87,  88,  92 
India-rubber  tree,  83 
Indusium,  7,  11 
Infundibulum,  125 
Inhalent  aperture,  59 
Intercellular  spaces,  84,  90 
Interclavicular  air-sac,  118 
Internode,  7 
Interstitial  cells,  55,  56 
Intestine,  71,  99,  113,  117,  119, 

129,  133,  144 
Iris,  126,  142 

Keel,  117 

Kidneys,  108,  114,  123,  138,  145 

Knee-joint,  142 

Labial  palps,  60,  61,  65 

Lateral  folds,  149 

Lateral  ventricle,  125 

Lamellae,  43,  44 

Lamina,  7 

Layer  cortical,  41,  42 

Layer  gonidial,  41 

Layer  medullary,  42 

Layer  muscular,  16 

Leguminosae,  86 

Lemna,  82 

Lens,  111,  126,  142,  150 

Ligament,  falciform,  117,  119 

Liliacese,  86 

Lily,  86 

Limbs,  96,  128,  152 

Lips,  128 

Liver,  98,  99,  101,  113,  119,  129, 

130,  145,  151 
Lobe,  7,  85 

Lobes,  olfactory,  107,  108,  140 

Lobes,  optic,  108 

Lobule,  7 

Lumbar  plexus,  124 

Liimbricus  terrestris,  13 

Lurnbro-sacral  plexus,  140 

Lungs,  93,  99,  145,  151 


158 


INDEX. 


Macronucleus,  81,  32 

MacrozoSspores,  28 

Mammae,  128 

Mandible,  74 

Mantle,  58,  59,  65 

Mantle-cavity,  60 

Mauus,  96,  129 

Mass,  visceral,  60,  61,  65 

Material,  27,  39,  48,  58,  66,  78, 

83 

Maxilla,  74 

Maxillary  process,  superior,  152 
Maxilliped,  73,  74 
Mechanical  experiments,  25 
Medulla,  138 
Medulla  oblongata,  108, 124,  140, 

141 

Medullary  folds,  143,  147,  148 
Medullary  layer,  42 
Medullary  rays,  78,  80 
Membrane,  tympanic,  96 
Mesenterou,  71 
Mesentery,  99,  117,  129,  130 
Mesoblast,  148 

somatic,  144,  148 

splanchnic,  144,  148 
Mesoblastic  somites,  148 
Mesocarpus,  50 
Mesonephros,  145 
Mesophyll,  11 
Metamerism,  14 
Methods,  13,  25,  36,  50,  53,  54, 

55,  58,  94,  95,  143 
Micrometer,  stage,  6 
Micronucleus,  31,  32 
Micropyle,  87,  88 
Microzoospore,  29 
Mitral  valve,  137 
Mnium,  76 

Monocotyledon,  81,  92 
Monro,  foramen  of,  109 
Motile  forms,  28,  29,  35 
Mouth,  14,  17,  30,  33,  52,  61,  67, 

97,  128,  143,  144,  152 
Movement,  Brownian,  45 
Muller,  86 
Muscle,  adductor,  58,  59 


Muscle,  gastrocnemius,  111 

papillary,  137 

pectoralis  major,  118 

pectoralis  minor,  118 

sartorius,  111 
Muscular  layer,  16 
Mustard,  82,  92 
Mycelium,  39,  40,  43,  44 

Narcissus,  86  * 

Nares,  anterior,  96 

posterior,  97 
Nasal  pits,  143,  150,  152 
Naso-frontal  process,  152 
Neck,  116,  128,  151 
Nematocyst,  53,  54,  55 
Nephridia,  16 
Nephridial  openings,  15 
Nerve,  brachial,  110 

branchial,  62 

cranial,  151 

olfactory,  107,  108 

optic,  140 

pallial  posterior,  62 

sciatic,  110 

septal,  21 

spinal,  110 

spinal  thoracic,  124 
Nerve-cord,  ventral,  21,  23 
Nerve-plexus,  brachial,  110,  124, 
140 

lumbar,  124 

lumbro  sacral,  140 

sciatic,  110,  124 
Nervous   system,   20,    106,   123, 

139,  140 

Nervous  system,  central,  20,  72, 
106 

peripheral,  21,  110,  124,  139 

sympathetic,  109,  123,  139 
Nettle-batteries,  53,  54 
Neural  tube,  144 
Mtella,  93 
Node,  7 
Nostrils,  128 
Notochord,  144,  148 
Nucellus,  87 


INDEX. 


159 


Nuclear  division,  94 

(Esophagus,    17,  30,  31,  33,  70, 

116,  119 
Oil-drops,  6 

Olfactory  lobes,  107,  108,  140 
Olfactory  nerves,  107,  108,  124 
Olfactory  pits,  151 
Olfactory  tract,  107,  108 
Ouion,  94 
Oophore,  75 
Oosphere,  12 
Opening,  urino-genital,  128 

excretory,  67,  139 

genital,  67 

nephridial,  15 
Operculum,  78,  113,  143 
Ophthalmic  artery,  69 
Optic  chiasma,  109,  125,  140 

commissure,  125 

lobes,  108,  124,  125,  126 

nerves,  140 

thalaini,  125,  141 

tracts,  140 

ventricle,  126 

vesicle,  150 
Ora  serrata,  126,  142 
Organ  of  Bojanus,  62,  65 
Ostia,  68,  69 

Ovary,  20,  70,  86,  105,  123,  138 
Oviduct,  15,  20,  70,  105, 123,  139 
Ovules,  85 

Palisade-cells,  84 
Pal  Hal  cavity,  60 
Palps,  labial,  60,  61,  65 
Pancreas,  99,  119,  122,  129,  145, 

151 

Pancreas,  duct  of,  129,  130 
Pansy,  87 

Papillary  muscles,  137 
Paraffine  thermometer,  25 
Paraphyses,  77 
Parenchyma,  cortical,  80 

fundamental,  8,  9,  81,  82 

sclerotic,  7 

wood,  81 


Parieto-splanchnic  ganglion,  62, 

65 

Parmelia,  41 
Pea,  87,  88.  90,  91,  92 
Pecten,  126 

Pectoralis  major  muscle,  118 
Pectoralis  minor  muscle,  118 
Pectoralis  secundus  muscle,  118 
Pedal  ganglia,  63 
Pedicel,  84 
Peduncles,  126 
Pelvic  cavity  of  kidney,  138 
Pelvis,  112 
Pericardia!  cavity,  61,  62,    114, 

151 

Pericardial  sinus,  68 
Pericardium,  145 
Perichaetium,  75 
Peripheral  nervous  system,  21. 

110 

Peristome,  33,  78 
Pes,  96,  129 
Petals,  85 

Pharynx,  17,  97,  145,  150 
Phloem,  80,  81 
Phloem-parenchyma,  10 
Phloem-sheath,  9 
Physiological  experiment,  38 
Pia  mater,  107 
Pileus,  43 

Pineal  gland,  107,  140 
Pinna,  7,  128 
Pinnula,  7 
Pistil,  84 
Pith,  80 
Pits,  79,  80 

Pituitary  body,  109,  125,  141 
Plasmolysis,  49 
Pleurococcus,  28,  29 
Plumule,  88,  89 
Pollen-grains,  85,  86 
Polytrichum,  75 
Pons  Varolii,  141 
Pontederia,  82 
Pores,  dorsal,  15 
Posterior  adductor  muscle,   59, 

61,  65 


160 


INDEX. 


Posterior  commissure,  125 
Posterior  median  seminal  vesicle, 

19 

Posterior  nares,  97 
Posterior  pal  Hal  nerve,  62 
Potato  cultures,  46,  47 
Pouch,  buccal,  17,  21 
Prebronchial  air-sac,  118 
Primitive  streak,  147,  148 
Primordial  utricle,  49 
Processes  ciliary,  126,  142 
Pronephros,  145 
Prosenchyraa,  82 
Prosenchyma  sclerotic,  8,  9 
Prostomium,  14 
Prothallium,  12 
Protonema,  78 
Proventriculus,  119,  122 
Pseudopodia,  24,  25 
Pteris  aquiliua,  7 
Pupil,  126,  142 
Pyloric  appendages,  114 
Pylorus,  130 
Pyramids,  141 
Pyrenoids,  49 

Quill,  126 

Rachis,  127 
Radial  symmetry,  53 
Radicle,  88,  89 
Rami  communicantes,  139 
Rays  medullary,  79 
Receptacle,  85 
Receptacles  seminal,  14,  20 
Rectal  cceca,  119 
Rectum,  65,  119 
Rete  mirabile,  114 
Retina,  111,  126,  142 
Rhizoids,  41,  75,  76 
Rhizome,  7,  8,  9,  10 
Rings  annual,  79 
Root,  7,  82,  92,  93,  94 
Root-cap,  82 
Root-hair,  82 
Root-sheath,  89 
Rosettes,  ciliated,  19 


Rotation,  29 

Sacs  scrotal,  128,  138 
Sartorius  muscle,  111 
Scale,  6 
Scales,  15 
Scaphognathite,  73 
Scapus,  126 
Sciatic  nerve,  110 

plexus,  110,  124 
Sclerenchyma,  8 
Sclerotic  coat,  111,  126,  142 

parenchyma,  7,  9 

prosenchyma,  8,  9 
Scrotal  sacs,  128,  138 
Scutellum,  89 

Sedgwick  and  Wilson,  19,  22,  36 
Seed-coats,  87,  89 
Seeds,  87 

Segmentation  stages,  frog,  143 
Semilunar  valves,  137 
Seminal  receptacles,  14,  20 

vesicles,  16,  19 

vesicle,  anterior  median,  19 

vesicle,  posterior  median,  19 
Sepals,  85 
Septal  nerves,  21 
Septum,  137 
Serial  symmetry,  141 
Seta,  14,  77 
Seta-sac,  22 

Sexual  generation,  12,  75 
Shaft,  127 
Sheath,  34 
Sieve-tubes,  9,  81 
Sinus,  pericardial,  68 

terminalis,  149 

venosus,  100,  102,  115,  145 
Skeleton  endophragmal,  72 
Somites,  13 

Somites  mesoblastic,  148 
Sorus,  7,  11 

Spaces,  intercellular,  84,  90 
Spermatozoa,  19 
Spermatozoid,  12 
Spinal  cord,  108,  109 

ganglia,  149 


INDEX. 


161 


Spiual  uerves,  110 

nerves,  thoracic,  124 
Spiue,  frontal,  66 
Spiral  vessels,  81,  82 
Spleen,  99,  114,  119,  122 
Sporangium,  7,  11 
Spore,  12,  39,  43,  77,  78 
Sporophore,  77 
Spot,  anal,  30 
Stage,  micrometer,  6 

warm,  25,  26 
Stalk,  34,  35 
Stamens,  84,  85 
Starch,  9,  10,  37,  89,  90,  93 
Stems,  126 
Sterigmata,  40,  44 
Sternal  artery,  69 

canal,  72 
Sternum,  117 
Stigma,  86 
Stipe,  7,  43 
Stoma,  10,  11,  83,  84 
Stomach,  64,  70.  99,  113,  129 
Stomach  intestine,  17,  18 
Strand,  axial,  76 
Streak,  primitive,  147,  148 
Subepidermis,  7,  8,  9,  76,  80,  81 
Subcesophageal  ganglion,  21 
Superior  abdominal  artery,  69 
Supporting  lamella,  56 
Suprabrauchial     chamber,     60, 

65 

Supracesophageal  ganglia,  72 
Symmetry,  bilateral,  14 

radial,  53 

serial,  14 
Sympathetic  ganglia,  110 

nervous  system,  109 
Symphysis  pubis,  138 
System,  eudophragmal,  72 

nervous,  20 

Tadpole,  144 
Tail,  116,  128,  145 
Tail-fold,  150 
Tapetum,  142 
Teeth,  97,  142,  144 


Teeth,  gastric,  71 
of  peristome,  78 
Tel  son,  73 

Testis,  20,  70,  94,  106,  123,  138 
Testis,  cell-division  in,  94 
Thalamencephalon,  107 
Thallus,  41,  42 
Theca,  85 

Thermometer,  parnffine,  25 
Third  ventricle,  125 
Thoracic  ganglia,  72 
Thorax,  128,  131 
Thymus,  131 
Tongue,  97 
Trachea,  116,  131 
Tracheae,  10,  81 
Tracheids,  10,  79,  80,  81 
Tradescantia,  93 
Trichocyst,  32 
Tricuspid  valve,  137 
Truncus  arteriosus,  100, 103 
Trunk,  96,  116,  128 
Tuber  cinereum,  109 
Tympanum,  96,  97 
Tympanic  membrane,  96 
Typhlosole,  18,  64 

Umbilicus  inferior,  127 

superior,  127 
Ureter,  106   123,  138,  139 
Uterus,  138 

Uterus  masculinus,  139 
Urethra,  139 
Urine-genital  opening,  128 

pouch,  123 
Urn,  147 
Utricle,  primordial,  49 

Vacuole,  40 

Vacuole,  contractile,  24,  31,  34 

food,  24,  31,  34 

water,  24,  31,  34 
Vagina,  138 
Valve,  mitral,  137 

semilunar,  137 

tricuspid,  137 
Vane,  127 


162 


INDEX. 


Vas  deferens,  15,  19,  70,  123, 138, 

139 

Vasa  efferentia,  106 
Vein,    abdominal    anterior,    98, 
100,  101,  102 

azygos,  132 

brachial,  103,  120 

caudal,  120 

coccygeo-iuesenteric,    120,  121 

coronary,  133 

epigastric,  119 

femoral,  101,  120 

gastric,  102,  121 

gastro-duodeual,  121 

genital,  102 

hepatic,    102,    113,    114,    121, 
133 

hepatic  portal,  102 

hepatic  portal  system,  121 

hypogastric,  120,  121 

iliac,  120,  134 

iliac,  external,  134 

iliac,  internal,  120, 134 

ilio-lumbar,  133 

innominate,  103 

intercostal,  132 

intestinal,  102 

jugular,  102,  103,  120,  133 

lingual,  103 

mammary  internal,  132 

maxillary  inferior,  103 

meseuteric  anterior,  121 

mesenteric  posterior,  120,  121 

musculo-cutaneous,  98,  103 

omphalo-mesenteric,  149 

ovarian,  133 

pectoral,  120 

pelvic,  101 

portal,  121,  134 

precaval,  115 

pulmonary,  122,  134 

renal  portal,  101 

renal,  102,  121,  133 

sciatic,  101,  121 

spermatic,  133 

splenic,  102 

subclavian,  103,  133 


Vein,  subscapular,  103 

vena  cava,  62,  65 

vena  cava  anterior,  120,    132, 

133 

inferior,  102 
posterior,  120,  133 
superior,  102,  103 

vertebral,  120,  132 

vitelline,  150,  151 

vitelline,  anterior,  150 
Velum,  43 

Ventral  nerve-cord,  21,  33 
Ventral  pyramids,  141 
Ventricle,  61,  05,  100,  115,  120, 

131,  145 

Ventricle,  fourth,  108,  109,  125, 
141 

lateral,  109,  125 

optic,  109,  126 

third,  109,  125,  141 
Vertebra,  142 
Vesicles,  auditory,  149 

of  braiu,  149,  151 

optic,  150 

seminal,  16,  19 
Vessels,  annular,  81,  82 

circular,  17 

spiral,  81,  82 
Vestibule,  30,  33 
Vexillum,  127 
Vibrissse,  128 
Violacese,  86 
Violarieae,  86 
Violet,  86,  87 
Visceral  arches,  152 

ganglion,  62,  65 

mass,  60,  61,  65 
Vitellus,  146,  147 
Vitreous  humor,  111,  126,  142 

Warm  stage,  25,  26 
Water-pore,  144 
Water- vacuole,  24,  31,  34 
Wheat,  87,  89,  90,  92 
Whiskers,  128 
Whorl.  84 
Wickersheimer's  fluid,  95 


INDEX. 


Wolffian  ducts,  149,  151 
Wood-pareuchyma,  10,  81 

Xylem,  10,  80,  81 
Yolk,  146,  147 


Yolk-stalk,  152 

Zoochlorella,  55 
Zooglcea,  46 
Zoospore,  28,  29 
Zyguerna,  50 


163 


January,  1898. 

HISTORY,  POLITICAL  SCIENCE, 
SOCIOLOGY,  LAW,  Etc. 

REFERENCE-  AND  TEXT- BOOKS. 

PUBLISHED    BY 

HENRY  HOLT  &  COMPANY,  29N*W  %DRKSr- 

Books  marked  *  are  chiefly  for  reference  or  supplementary  use,  and  may 
be  found  in  Henry  Holt  &>  Go's  List  of  Books  for  School  Libraries.  Books 
not  so  marked  are  more  fully  described  in  the  publishers'  Descriptive  Educa- 
tional Catalogue,  and  may  also  be  had  at  their  Chicago  branch,  378  Wabash 
Avenue.  Either  of  these  Catalogues  or  the  publishers'1  Catalogue  of  Works  in 
General  Literature  sent  free.  Postage  on  NET  books,  %%  additional. 

PRICE 

Adams'  The  Science  of  Finance.  By  Prof.  H.  C.  Adams  of  Univ.  of 
Mich.  (In  preparation.) 

*Bazin1s  The  Italians  of  To-day.     247  pp.     12010 $125 

Bolles'  Elements  of  Commercial  Law.     With  very   full   summaries 

and  index.     344  pp.     12010   net     i  oo 

Burke  ;  Speeches  on  arrival  at  Bristol,  at  Conclusion  of  the  Poll, 
Letters  to  the  Marquis  of  Rockingham.  to  the  Sheriffs  of  Bristol, 
and  to  a  Noble  Lord,  and  other  Selections.  Edited  by  Prof. 

Bliss  Perry  of  Princeton,  xxvi  +  298  pp.   i6mo net    060 

*Champlin's  Young  Folks'  History  of  the  War  for  the  Union.  Il- 
lustrated. 606  pp.  8vo a  50 

*Chevrillon's  In  India.     Masterly  descriptions  of  Hindu  India  to  day. 

265  pp.     i2mo 150 

*Cory's  Guide  to  Modern  English  History. 

Part    I.  1815-1830.     276  pp.     8vo  2  oo 

Part  II.  1830-1835.     576  pp.     8vo 3  50 

*Cox's  Introduction  to"the  Science  of  Comparative  Mythology  and 

Folk-lore.     396  pp.     121110.... 175 

*Creasy's  History  of  the  Ottoman  Turks.     568  pp.     12010 250 

*Dabney's  Causes  of  the  French  Revolution.     By  Prof.  R.  H.  Dab- 

ney  of  the  University  of  Virginia.     307  pp.     i2ino ...     125 

*Doyle's  English  Colonies  in  America.  By  J.  A.  Doyle,  Fellow  of 
All  Souls'  College,  Oxford.  8vo. 

Vol.  I.  Virginia,  Maryland,  and  the  Carolinas.     420  pp 350 

Vols.  II.  &  III.  The  Puritan  Colonies.     333  +  416  pp 700 

*Durand's  New  Materials  for  the  History  of  the  American  Revo- 
lution. Translated  from  documents  in  the  French  archives  and 

edited  by  John  Durand.     317  pp.     i2mo 175 

Duruy's  Middle  Ages.  Translated  by  E.  H.  and  M.  D.  Whitney.  Ed- 
ited by  Prof.  Geo.  B.  Adams  of  Yale.  With  13  new  colored 

maps.     603  pp.     12010 net    i  60 

Modern   Times  (1453-1789).     Translated  by  Edwin  A.  Grosvenor. 

With  5  colored  maps.     575  pp.     12010 net    i  60 

*Escott's  England  :  Her  People,  Polity,  and  Pursuits.    625  pp.    8vo.     400 

I 


Henry  Holt  £r  Co.'s  Works  on  History,  etc. 


PRICE 

*Falke's  Greece  and  Rome  :  Their  Life  and  Art.  With  400  illustra- 
tions. 365  pp.  410 $io  oo 

Fleury's  Ancient  History,  Told  to  Children.  Translated  and  edited 
for  schools  as  an  exercise  for  translating  from  English  into 
French  by  Susan  M.  Lane.  118  pp.  12010 net  70 

Ford's  Federalist.  A  definitive  edition  edited  by  Paul  Leicester  Ford. 
With  foot-notes  showing  relations  of  subsequent  events  to  the 
views  in  the  text,  an  appendix  of  100  pages,  including  the  Consti- 
tution and  references  to  court  decisions  regarding  it,  a  full  and 
reliable  index,  and  other  special  features.  Large  12010.  (In 
press:  circular  free?) 

Fournier's  Napoleon.  A  compact,  impartial,  and  reliable  life.  Edited 
by  Prof.  Edward  G.  Bourne  of  Yale.  {In  preparation.} 

FREEMAN'S  HISTORICAL  COURSE.  Under  the  general  editor- 
ship of  the  late  Prof.  Edward  A.  Freeman  of  Oxford.  The 
editors  of  the  various  volumes  have  especially  adapted  them  for 
America.  i6mo. 

1.  General  Sketch  of  History.  By  Prof.  E.  A.  Freeman.  Newedition, 

revised,  with  chronological  table,  maps,  and  index.     432  pp.  .net  i  10 

2.  England.     By  Edith  Thompson.     400  pp net  38 

3.  Scotland.     By  Margaret  Macarthur.     213  pp net  80 

4.  Italy.     By  William  Hunt.     285  pp  net  80 

5.  Germany.     By  James  Sime.     282  pp net  80 

6.  The  United  States.     By  J.  A.  Doyle.     With    maps,  illustrative 

of  the  acquisition  of  territory  and  the  increase  of  population,  by 
Francis  A.  Walker.     424  pp.   . . . net     i  oo 

7.  France.     By  Charlotte  M.  Yonge.     267  pp net        80 

Fyffe's  Modern  E'urope.     By  the  late  C.  A.  Fyffe,  M.A.,  Barrister-at- 

Law;  Fellow  of  University  College,  Oxford;  Vice-president  of 
the  Royal  Historical  Society.    8vo. 

Vol.      I.  From  1792  to  1814.     With  two  maps.     549  pp 250 

Vol.    II.  From  1814  to  1848.     525  pp 2  50 

Vol.  III.  From  1848  to  1878.     580  pp 250 

Modern  Europe  (1792-1878)  unabridged.    One  volume  edition.     1120 

pp.     12010 net    2  75 

Gallaudet's  International  Law.    A  Manual.     By  Pres.  E.  M.  Gallaudet 

of  College  for  Deaf- Mutes,  Washington.     358  pp.     12010 net    i  30 

Gardiner's  English  History  for  Schools.  B.C.  SS-A.D.  1880.  By 
Prof.  S.  R.  Gardiner  of  King's  College,  London.  Edition  re- 
vised for  American  students.  497  pp.  i6mo net  80 

Introduction  to  English  History.     209  pp.     12010 net        80 

English  History  for  Students.  Being  the  Introduction  to  Eng- 
lish History  by  Prof.  S.  R.  Gardiner.  With  a  critical  and  bio- 
graphical account  of  the  authorities  by  J.  Bass  Mullinger,  448 

pp.     i2tno net     \  80 

Gordy's  Political  Parties  in  the  United  States.  Vol.  I.  1787-1809. 
(In  preparation.) 

*Ihering's  The  Evolution  of  the  Aryan.     412  pp.     8vo net    300 

*Jackson's  (Lady)  Old  Paris,  Its  Courts  and  Literary  Salons.     537  pp. 

i2mo ..    225 

The  Old  Regime,  Court,  Salons,  and  Theatres.     532  pp.     12010 2  25 

Jenks'  Law  and  Politics  in  the  Middle  Ages.  (In preparation} 
Johnston's  History  of  the  United  States  for  Schools.  With  an  intro- 
ductory history  of  the  discovery  and  English  colonization  of 
North  America.  By  the  late  Prof.  Alexander  Johnston  of  Prince- 
ton. Revised  and  continued  to  1897  by  Prof.  W.  M.  Daniels  of 
Princeton.  With  maps,  plans,  illustrations,  questions,  a  bibli- 
ography, etc.  499  pp.  i2mo.  Half  roan net  i  oo 


Henry  Holt  &  Co.'s  Works  on  History,  etc. 


PRICE 

Johnston's  Shorter  History  of  the  United  States.     With  references 

to  supplementary  reading.     356  pp.     ismo ...  -net  $o  95 

History  of  American  Politics.     Revised   and   enlarged  by  Prof. 

Wm.  M.  Sloane  of  Princeton.     366  pp.     i6mo net        80 

Lacombe'sThe  Growth  of  a  People.     A  translation  of  "  Petite  Histoire 

du  Peuple  Fran9aise."     232  pp.     i6mo net        80 

The  same  in  French net       60 

*Lossing's  Life  and  Times  of  Major-General  Philip  Schuyler.     2 

vols.     With  portraits.     520  +  560  pp.     12010 350 

*Maine's  Ancient  Law.  Its  Connection  with  the  Early  History  of 
Society,  and  its  Relation  to  Modern  Ideas.  By  Sir  Henry 
Sumner  Maine.  With  an  introduction  by  Theo.  W.  Dwight, 

LL.D.     469  pp.     8vo ..   ..     350 

*Lectures  on  the  Early   History  of  Institutions.     A  Sequel  to 

"  Ancient  Law."     420  pp.     8vo 350 

*Village  Communities  in  the  East  and  West.     Six  Oxford  Lec- 
tures; to  which  are  added  other  lectures,  addresses,  and  essays. 

425  pp.     8vo 350 

*Early  Law  and  Custom.     Taken  chiefly  from  Oxford  Lectures. 

408  pp.    8vo 350 

*Popular  Government.     Four  Essays.     273pp.     8vo 275 

*International  Law.     Cambridge  Lectures,  1887.     234  pp.    8vo...      275 
*Maine,  Sir  Henry.     A  Brief  Memoir  of  his  Life  by  Sir  M.  E.  Grant 
Duff,  with  some  of  his  Indian  Speeches  and  Minutes.     Edited 

by  Whitley  Stokes.     With  portrait.    451  pp.    8vo 350 

*Mill's  Considerations  on   Representative    Government.     By  John 

Stuart  Mill.     371  pp.     8vo   200 

*On  Liberty  :  The  Subjection  of  Women.     394  pp.     8vo 200 

*Morgan's  Ancient  Society  ;  or,  Researches  on  the  Lines  of  Human 
Progress  through  Savagery  and  Barbarism  to  Civilization.  By 

Lewis  H.  Morgan,  LL.D.     576pp.     8vo 400 

*Pollard's  Political  Pamphlets.  Pamphlets  by  Burke,  Steele,  Saxby, 
Halifax,  Arbuthnot,  Swift,  Bolingbroke,  and  "Junius,"  that 
have  done  much  to  shape  English  history.  Bound  in  i  vol.  345 

pp.     i2tno 175 

Porter's  Outlines    of   the   Constitutional    History   of  the   United 

States.     By  Luther  Henry  Porter.     326pp.     i2mo net     i  20 

Ringwalt's  Modern  American  Oratory.  Selected  representative 
Speeches.  Edited  by  R.  C.  Ringwalt  of  Columbia.  (In  prep- 
aration.) 

*Roscher's  Principles  of  Political  Economy.  By  Prof.  Wm.  Ro- 
scher  of  Leipzig.  With  a  preliminary  essay  by  L.  Wolowski. 

2  vols.     485  -f  465  pp.     Svo net    7  oo 

*Rowan  and  Ramsay's  The  Island  of  Cuba.  With  bibliography,  col- 
ored maps,  points  of  International  Law  bearing  on  the  Cuban 
Question,  President  Grant  on  Cuba  (1875),  etc.  279  pp.  i6mo..  i  25 
*Sumner1s  History  of  American  Currency.  By  Prof.  Wm.  Graham 
Sumner  of  Yale.  With  chapters  on  the  English  Bank  Restriction 
and  Austrian  Paper  Money.  To  which  is  appended  "  The 

Bullion  Report."     With  diagrams.     391  pp.     Large    i2mo 300 

*Essays  in  Political  and  Social  Science.     176  pp.     Svo  150 

Protectionism.      The    "  ism "   which  teaches    that  waste    makes 

wealth.     181  pp.     i6mo i  oo 

Problems  in  Economics.     Interleaved.     137  pp.     i6mo net     TOO 

3 


Henry  Holt  &  Co.'s  Works  on  History,  etc. 


PRICK 

*Symonds'  Renaissance  in  Italy.     By  John  Addington  Symonds. 

Part      I.  Age  of  Despots.     653  pp.     8vo $200 

Part    II,  The  Revival  of  Learning.     561  pp.     8vo 200 

Part  III.  The  Fine  Arts.     548pp.     8vo.  ...     200 

Part  IV.  Italian   Literature.     With   portrait    of    author.    2    vols. 

576  -j-  653  pp.     8vo  4  oo 

Part    V.  The    Catholic    Reaction,     z    vols.     445  +  441  pp.     8vo..     400 

*Short  History  of  the  Renaissance.     235  pp.     121110 i  75 

•"Italian  Byways.     318  pp.     izmo .     .     i  75 

*Taine1s  Ancient  Regime.     By  Hippolyte  Adolphe  Taine.    Translated 

by  John  Durand.     Library  edition.     437pp.     i2mo 250 

*French  Revolution.    Translated  by  John  Durand.    3  vols.    367  + 

37°  +  523  PP-     lamo 7  50 

The  Modern  Regime.     2  vols.     371  + •  297  pp.     i2mo each    250 

*Journeys  through  France.     Impressions  of  the  Provinces.     Illus- 
trated.    296  pp.     i2mo 250 

*Tylors  Primitive  Culture.  Researches  into  the  Development  of 
Mythology,  Philosophy,  Religion,  Art,  and  Custom.  2  vols. 

514  +  478  pp.     8vo  700 

*Researches  into  the  Early  History  of  Mankind  and  the  Devel- 
opment of  Civilization.     392  pp.     8vo.. 350 

Wagner's  Modern  Political  Orations  (England  1838-88).  Twenty- 
four  Speeches.  By  Macaulay,  Fox,  Cobden,  Bulwer  Lytton, 
Morley,  Beaconsfield,  Gladstone,  Parnell,  etc.  xv-j-344  PP- 

i2ino net    100 

*Walker's  Wages.     A  Treatise  on  Wages  and  the  Wages  Class.     By 

Francis  A.  Walker.     432pp.     8vo 200 

*Money.     560  pp.     8vo 200 

*Money  in  its  Relations  to  Trade  and  Industry.     343  pp.     i2mo.     i  25 

Political  Economy— Advanced  Course.     545  pp.     8vo net    200 

Political  Economy— Briefer  Course.     423pp.     12010 net     120 

Political  Economy— Elementary  Course.    333  pp.     i2mo net    i  oo 

*International'Bimetallism.     297  pp.     12010 125 

*Wallace1s  Russia.    Social  conditions,  politics,  etc.,   to-day.    633  pp. 

8vo 2  oo 

Yooge's  Landmarks  of  History.     By  Miss  C.  M.  Yonge.     i2mo. 

Ancient  History  to  the  Mahometan  Conquest.     Revised  and  partly 

rewritten  by  Miss  Edith  M.  Chase.     231  pp net    075 

.     Edit 


Mediaeval  History  to  the   Reformation.     Edited  by   Miss  Chase. 

258  pp net    o  80 

Modern  History.     Revised.    486  pp net    105 

Postage  on  NET  books  8  per  cent  additional, 

4 


DATE  DUE  SLIP 

UNIVERSITY  OF  CALIFORNIA  MEDICAL  SCHOOL  LIBRARY 

THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


